1599 resistance change ranging from 5500% to 500%$^{405}$. In another study, Han et al. 15 devised a similar humidity 1600 sensor using cellulose paper embedded with carbon nanotubes, exhibiting a linear response up to a relative 1601 humidity of 75%. Both sensors displayed high reproducibility and long-term stability$^{15,405}$. The conductance 1602 shift of the nanotube network entangled within the cellulose matrix served as the basis for humidity sensing. 1603 The sensor exhibited a linear response behavior up to a relative humidity of 75%, with excellent repeatability 1604 and minimal hysteresis$^{15}$. Figure 21B depicts the configuration of the developed humidity sensor, 1605 showcasing its design and functionality$^{15}$. These innovative approaches highlight the potential of carbon 1606 nanotube-cellulose composites in the development of highly sensitive and reliable humidity sensing devices 1607 $^{15,405}$. Moreover, Yun et al. 393 prepared a chemical vapor sensor using a composite of MWCNTs and cellulose 1608 paper. This sensor was capable of detecting vaporized analyte molecules such as methanol, ethanol, 1- 1609 butanol, and 1-propanol, demonstrating reversible and rapid relative resistance responses contingent upon 1610 the concentration of the analytes$^{393}$. This underscores the potential of the paper-based chemical sensor 1611 for sensitive and selective detection of various vaporized compounds$^{393}$. Figure 21C visually illustrates the 1612 configuration and functionality of the developed paper-based chemical sensor, showcasing its promising 1613 capabilities in chemical sensing applications (Figure 21D).

<figure><img src="image_41.png" /><figcaption>**Figure 21:** (A) The design of a disposable molecular sensor made with ZnO metal oxides, cellulose nanofibers, and pencil-drawn electrodes. Reproduced with permission from Ref. 316, Copyright © 2019 American Chemical Society. (B) a) A humidity sensor on cellulose paper, (b) flexible and customizable CNT networks, (c) SEM image of cellulose paper, and (d) magnified cross-linked CNTs. Reproduced with permission from Ref. 15, Copyright © 2012 American Chemistry Society. (C) A developed paper-based chemical sensor, and (D) its electrical response to specific chemicals. Reproduced with permission from Ref. 393, Copyright © 2010 Elsevier.</figcaption></figure>

1614

1615

1616

1617

1618

1619

1620

1621

1622

1623

1624

1625

Xu et al. 406 developed highly sensitive thin-film sensors for alcohol recognition were utilizing graphene-based materials. Figure 22A provides a visual representation of the thin-film sensors developed in this study, illustrating their structure and potential for alcohol recognition with enhanced sensitivity$^{406}$. They ingeniously assembled graphene nanosheets (GNs) with bacterial cellulose
nanofibers (BCNs) to create a thin-film alcohol-sensing device. The GN/BCN sensor exhibited significantly higher sensitivity towards vapor-phase ethanol than sensors using pure graphene nanosheets ⁴⁰⁶. It demonstrated fast response and recovery times and could detect alcohol in the range of 10% to 100% (Figure 22B) ⁴⁰⁶. Furthermore, Veeralingam et al. ⁴⁰⁷ introduced a one-step process to fabricate cellulose paper by directly growing NiSe₂, resulting in a low-cost, flexible, wearable multifunctional sensing platform that integrates with smartphones ⁴⁰⁷. This platform demonstrated remarkable utility in various healthcare applications, including non-invasive periodontal diagnosis for oral health monitoring utilizing human saliva analysis ⁴⁰⁷. Additionally, it served as a breath analyzer for detecting various breath-related diseases and as a gesture sensor facilitating communication for individuals with hearing impairments. This multifunctional sensing platform represents a significant advancement in personalized healthcare monitoring, offering a seamless and accessible solution for diverse healthcare needs ⁴⁰⁷. Additionally, Morales-Narváez and co-workers ⁴⁰⁸ conducted pioneering work in constructing a nanopaper as an optical sensing platform for a range of biologically relevant analytes (Figure 22C). They demonstrated the superiority of bacterial cellulose (BC) as a preconcentration platform, enabling the analysis of small volumes of optically active materials, approximately 4 µL. To create the sensing platform, they printed spots on bacterial cellulose plates, including cuvettes, to develop a colorimetric-based sensor ⁴⁰⁸. The sensor was developed using nanopaper embedded with silver and gold nanoparticles (AuNPs) to design the nanopaper-based composites. In Figure 22D(a), the colorimetric profiles of bare BC and nitrocellulose spots, drop-casted with AuNPs, showed BC 2.4-fold signal enhancement, indicating its preconcentration ability. BC also improved measurements of small volumes of optically active nanomaterials like AuNPs and quantum dots (QDs), as shown in Figure 22D(b) ⁴⁰⁸.

<figure><img src="image_42.png" /></figure>

<figure><img src="image_43.png" /></figure>
**Figure 22:** (A) Illustration of the assembly process from raw material to thin-film sensor device (from a to g). Reproduced with permission from Ref. ⁴⁰⁶, Copyright © 2017 Springer Nature. (B) (a) Resistivity changes of 225-nm-thick and 833-nm-thick GN/BCN sensors under varying relative humidity (RH). (b) Sensitivity of GN/BCN sensors to different %RH levels. (c) Electrical configuration models in thick and thin GN/BCN films. (d) Experimental setup for evaluating GN/BCN sensor response to alcohol or water vapors. (e) Sensitivity of GN/BCN sensors detecting liquid-phase ethanol and water. Reproduced with permission from Ref. ⁴⁰⁶, Copyright © 2017 Springer Nature. (C) Various steps (from a to d) in the creation of nanopaper-based composites. Reproduced with permission from Ref. ⁴⁰⁸, Copyright © 2015 American Chemical Society. (D) Use of nanopaper as a preconcentration platform: (a) Colorimetric profile and images of AuNP deposited on bacterial cellulose nanopaper (BC) and nitrocellulose (nitroC). (b) UV-vis/photoluminescent spectra of 4 µL of [AuNP] = 1.84 µM and 4 µL of [QDs] = 100 nM on BC and microwells, respectively. QDs were excited at 480 nm. Reproduced with permission from Ref. ⁴⁰⁸, Copyright © 2015 American Chemical Society.

(c) 3D nanocellulose substrates based (bio)sensors: In the realm of (bio)sensors, 3D nanocellulose substrates have garnered significant attention due to their unique properties and versatility. These substrates, often in the form of hydrogels, are characterized by their water-swelling ability and are typically formed through chemical or physical crosslinking processes. Hydrogels, which constitute polymer gels, are defined as 3D networks that can absorb large quantities of water. Nanocellulose, owing to its exceptional matrix or support capabilities, serves as an ideal platform for a wide array of biomolecules ⁴⁰⁸,⁴⁰⁹. Ruiz-Palomero et al. ⁴¹⁰ pioneered the development of a nanostructured conductive hydrogel-based sensor utilizing cellulose nanocrystals. This sensor incorporated photosensitive ruthenium bipyridine moieties for the detection of silver nanoparticles in real samples, as depicted in Figure 23A. They engineered flexible luminescent gels based on carboxylated nanocellulose platforms, demonstrating excellent sensing performance with a broad response range of 1.85×10⁻⁵ to 1.48×10⁻⁴ mol L⁻¹ and a detection limit (LOD) of 1.11×10⁻⁵ mol L⁻¹ ⁴¹⁰. Similarly, Wang et al. ⁴¹¹ explored the modification of nanofibrillated cellulose aerogels with carbon nanotubes to achieve mechanoresponsive conductivity and pressure sensing capabilities. By combining nanocellulosics and carbon nanotubes, they envisioned a wide range of responsive electroactivity, pressure sensing, and functional materials, harnessing the strengths of both components for larger-scale applications. In another study, Ruiz-Palomero et al. ⁴¹² summarized various sensing materials based on nanocellulose for the determination of diverse target analytes, as depicted in Figure 23B. This comprehensive exploration underscored the potential of nanocellulose-based substrates in enabling advanced sensing platforms for a multitude of applications, ranging from environmental monitoring to biomedical diagnostics ⁴¹².

<figure><img src="image_44.png" /></figure>

<figure><img src="image_45.png" /></figure>
**Figure 23:** (A) Illustration of the sensor and electrochemical response to chemicals tested. Reproduced with permission from Ref. ⁴¹⁰, Copyright © 2016 Elsevier. (B) Analytical applications of different fluorescent nanocellulose based hydrogels with remarkable performances for enzyme immobilization and toward diverse target analytes. Reproduced with permission from Ref. ⁴¹², Copyright © 2017 Elsevier.

Hydrogels are increasingly recognized as prime candidates for supercapacitors owing to their flexible three-dimensional (3D) networks, remarkable deformability, and inherent hydrophilic nature. The success of superior supercapacitors hinges on the seamless integration of these properties alongside suitable electrode materials and electrolytes. Wang et al. ⁴¹³ developed conductive hydrogels utilizing (TEMPO)-cellulose nanofibers, carbon nanotubes (CNTs), and polyaniline (PANI) hybrids for application in flexible supercapacitors, illustrated in Figure 24A. CV was used to evaluate the composite hydrogel electrochemical behavior ⁴¹³. PANI-enhanced hydrogels exhibited higher capacitance, indicated by increased current density and distinct oxidation-reduction peaks (Figure 24B). This composite hydrogel boasted a low density (~1.2 g cm⁻³), high water content (~95%), exceptional flexibility, self-healing capability, notable electrical conductivity (15.3 S m⁻¹), and a specific capacitance of 226.8 F g⁻¹ at 0.4 A g⁻¹ ⁴¹³. Furthermore, the combination of cellulose nanofibers (CNFs) modified with quaternary amine groups via polypyrrole (PPy) polymerization exhibited impressive electrical characteristics, including high gravimetric and volumetric capacitances of 127 F g⁻¹ and 122 F cm⁻³, respectively, based on electrode mass/volume at current densities up to 300 mA cm⁻² (or 33 A g⁻¹). Additionally, device-specific volumetric energy and power densities of 3.1 mWh cm⁻³ and 3 W cm⁻³ were achieved (Figure 24C) ⁴¹³. A lot of research works related on the utilization of nanocellulose based composite hydrogels as electrode materials for the development of supercapacitors have been largely reported in the literature ⁴¹⁴⁻⁴²². These works exploited the good biodegradability, mechanical flexibility, electrical conductivity and chemical reactivity of nanocellulose to develop such excellent storage energy devices. Numerous studies have extensively explored the utilization of nanocellulose-based composite hydrogels as electrode materials in the development of supercapacitors, leveraging the biodegradability, mechanical flexibility, electrical conductivity, and chemical reactivity of nanocellulose. These endeavors, documented in the literature, underscored the immense potential of nanocellulose-based materials in advancing energy storage devices, offering a pathway towards sustainable and high-performance energy solutions ⁴¹⁴⁻⁴²².
<figure><img src="image_46.png" /><figcaption>**Figure 24:** (A) Illustration of the TOCNF-CNT@PANI/PVA composite hydrogel fabrication process: (a) TOCNFs dispersion, (b) CNTs dispersion, (c) TOCNF-CNT nanohybrids, (d) TOCNF-CNT@PANI nanohybrids, (e) TOCNF-CNT@PANI/PVA hydrogel. (B) Electrochemical analysis: (a) CV curves, (b) G-CD curves, (c) specific capacitance at different current densities, (d) Nyquist plot. (E) (a) Self-healing mechanism and (b-e) electrochemical responses of supercapacitors. Reproduced with permission from Ref. 413, Copyright © 2020 MDPI</figcaption></figure>

**Challenges and opportunities in cellulose nanofibers based-(bio)sensors.** Nanocellulose, derived from Lignocellulosic biomass, has emerged as a promising candidate for various applications due to its unique properties such as high surface area, biocompatibility, renewability, and sustainability. Among its many potential uses, sensing applications have garnered significant attention in recent years. However, a critical review reveals several challenges and limitations that need to be addressed before its widespread adoption. One primary challenge is the inherent variability in nanocellulose properties, such as size, shape, surface chemistry, and crystallinity, which depend on the source material, extraction method, and processing conditions. This variability can significantly impact the performance and reliability of sensing devices. Additionally, nanocellulose-based sensor sensitivity to environmental factors like temperature,
1725 humidity, and pH can affect measurement accuracy and reliability. Furthermore, the detection limits may not always meet the requirements for certain applications, limiting practical utility. Integrating 1726 nanocellulose into sensing devices presents technical challenges, such as ensuring uniform deposition 1727 and immobilization on sensor substrates and maintaining compatibility with other materials and 1728 components, like electrodes and transducers, to prevent interference. Despite these challenges, 1729 researchers have made significant progress. Strategies such as surface modification, functionalization, 1730 and composite formation have enhanced the properties and performance of nanocellulose-based sensors. 1731 Advances in extraction and processing techniques have led to materials with improved consistency and 1732 reproducibility. In summary, while nanocellulose holds great promise for sensing applications, addressing 1733 its challenges and limitations is essential. Further research is needed to optimize properties, enhance 1734 sensitivity and reliability, and enable integration into practical devices. With continued efforts and 1735 advancements, nanocellulose-based sensors could revolutionize sensing technologies in healthcare, 1736 environmental monitoring and food safety. 1737

1738
2.5. Hemicellulose and sensor technology

1739
2.5.1. Hemicellulose structure and extraction

1740 Hemicellulose, an essential component of Lignocellulosic biomass, contributes significantly to the
1741 structural integrity and biochemical characteristics of plants ⁴²³. Unlike cellulose, which consists of linear
1742 chains of glucose molecules, hemicellulose is a heterogeneous polymer composed of various
1743 monosaccharides such as xylose, arabinose, mannose, galactose, and glucose (Figure 25) ⁵⁴,⁴²³.
1744 Hemicellulose molecules are branched polysaccharides with a backbone of repeating sugar units and side
1745 chains attached. This structure varies among plant species and tissues, contributing to the diversity of
1746 Lignocellulosic biomass ⁴²⁴,⁴²⁵. In hardwoods, hemicellulose is primarily composed of glucuronoxylan,
1747 while in softwoods, it mainly consists of glucomannan, with smaller amounts of glucuronoxylan. The
1748 structure and composition of hemicellulose can vary significantly depending on the plant species ⁴²⁶.
1749 Hemicellulose forms an amorphous matrix surrounding cellulose microfibrils in the plant cell wall,
1750 providing flexibility and resilience to withstand mechanical stress and environmental factors ⁴²³,⁴²⁷. It
1751 interacts with cellulose and lignin, contributing to the overall integrity and functionality of the plant cell
1752 wall ⁵³,¹⁷⁷. Techniques such as nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy have
1753 revealed the complex arrangement of sugar units and side chains within hemicellulose molecules.
1754 Hemicellulose serves as a renewable feedstock for various industrial applications, including biofuel
1755 production, food additives, and biodegradable polymers. It is characterized by β-(1→4)-linked backbones
1756 with an equatorial configuration, and includes polysaccharides such as xyloglucans, xylans, mannans,
1757 glucomannans, and β-(1→3,1→4)-glucans ⁴²⁸,⁴²⁹. Unlike cellulose, hemicelluloses have a random,
1758 amorphous structure with limited strength, making them susceptible to hydrolysis by dilute acids, bases,
1759 and hemicellulase enzymes. They are composed mainly of pentoses, hexoses, and carboxylic acids,
1760 forming branched chains that are partially soluble in water. Hemicelluloses account for 25 to 35% of
1761 Lignocellulosic biomass and have a degree of polymerization ranging from 100 to 300 units. The most
1762 common types of hemicelluloses include xylans, mannans, and galactans ⁴³⁰,⁴³¹. Hemicelluloses are the
1763 second most abundant component in lignocellulosic biomass after cellulose, accounting for one-fourth to
1764 one-third of plant matter. Their short, branched lateral chains form a network by hydrogen bonding with
1765 cellulose microfibrils and covalent bonding with lignin, contributing to the rigidity and structural integrity
1766 of the cellulose-hemicellulose-lignin matrix<sup>423,429</sup>.

<figure><img src="image_47.png" /><figcaption>**Figure 25:** Typical hexoses and pentoses found in hemicellulose. Reproduced with permission from Ref. ¹²⁷, Copyright © 2013 Royal Society of Chemistry. Chemical structure of hemicellulose structure. Reproduced with permission from Ref. ⁴³², Copyright © 2017 Elsevier.</figcaption></figure>

1767

1768

1769

1770

1771

1772

1773

1774

1775

1776

1777

1778

1779

1780

1781

1782

1783

1784

1785

1786

1787

1788

1789

1790

1791

1792

1793

1794

1795

Hemicellulose extraction from Lignocellulosic biomass is a critical process that involves breaking down the complex structure of plant cell walls to isolate this polysaccharide component ⁴²⁴,⁴³³. Sources such as wood, agricultural residues, and energy crops are rich in hemicellulose, which is valuable for biofuels, biomaterials, and biochemicals. The process begins with pretreatment using physical, chemical, or biological methods to disrupt the biomass and remove lignin, enhancing hemicellulose accessibility ⁴³²,⁴³⁴. Extraction methods include acid hydrolysis, alkaline extraction, steam explosion, and enzymatic hydrolysis. The extraction of hemicellulose from biomass using alkaline or acid pretreatment is a crucial step in the valorization of Lignocellulosic biomass. Alkaline pretreatment involves the use of bases like sodium hydroxide to break the ester and ether bonds between hemicellulose and lignin, effectively dissolving hemicellulose from the cell wall ⁴³⁵. This method is particularly effective because it disrupts the complex structure of the biomass, making hemicellulose more accessible. On the other hand, acid pretreatment typically uses dilute acids such as sulfuric acid to hydrolyze the hemicellulose into its monomeric sugars ⁴³⁵. This process not only facilitates the extraction but also enhances the subsequent fermentation processes by increasing the yield of fermentable sugars. Both methods are integral to improving the efficiency of biomass conversion into valuable bioproducts ⁴³⁵,⁴³⁶. Enzymatic hydrolysis, a more environmentally friendly method, utilizes enzymes to selectively hydrolyze hemicellulose under mild conditions, yielding higher amounts with minimal degradation. The extracted hemicellulose-rich liquor is then separated and purified through filtration, precipitation, or chromatography. Enzymatic extraction of hemicellulose from lignocellulosic biomass is a highly efficient and environmentally friendly method that utilizes specific enzymes to break down complex plant materials ⁴³⁵,⁴³⁶. This process involves the use of hemicellulases, which target the hemicellulose component within the lignocellulosic matrix, facilitating its release without significant degradation. Compared to traditional chemical extraction methods, enzymatic extraction preserves the structural integrity of hemicellulose, making it suitable for high-value applications such as biofuels, bioplastics, and other biochemicals ⁴³⁶,⁴³⁷. Additionally, enzymatic methods reduce the need for harsh chemicals and lower energy consumption, aligning with sustainable and green chemistry
principles. Purified hemicellulose serves as a renewable alternative to fossil-based materials across various industries. In biofuels, hemicellulose-derived sugars are fermented into bioethanol. In biomaterials, hemicellulose can be processed into films, coatings, adhesives, and composites ⁴³⁸. It is also used in the synthesis of value-added chemicals and pharmaceuticals. The choice of extraction method depends on the feedstock composition, desired purity, and application. Hemicellulose extraction is crucial for utilizing biomass sustainably and supporting a bio-based economy ⁴²⁴,⁴³⁸.

## 2.5.2. Hemicellulose properties

Hemicellulose, a complex carbohydrate polymer, is a key component of plant cell walls, alongside cellulose and lignin. Its presence contributes to the structural integrity, flexibility, and elasticity of plant tissues due to its composition of various sugar units such as xylose, glucose, and arabinose ⁴³⁸. One of the defining properties of hemicellulose is its heterogeneity, meaning its composition and structure can vary significantly depending on the plant species, tissue type, and growth conditions ⁴³⁶,⁴³⁷. Another important characteristic of hemicellulose is its solubility in water and alkali solutions, in contrast to cellulose, which is water-insoluble. Hemicellulose can be easily extracted from plant materials using mild alkali treatments, making it a valuable renewable resource for various industrial applications, including biofuels, bioplastics, and food additives ⁴³⁶,⁴³⁸. Additionally, hemicellulose exhibits unique rheological properties, influencing the texture of both plant cell walls and food products. Its role in the cell wall is to strengthen the structure by interacting with cellulose and lignin, providing stability and biodegradability for industrial use ⁴³⁹. Their hydrophilic nature and low molecular weight enable hydrothermal extraction and hydrolysis, while their chemical modification enhances their potential in various applications such as selective membrane materials ⁴⁴⁰. Hemicelluloses are a mixture of different monomer sugars, and they are heteropolysaccharides with short chains having a degree of polymerization between 150 and 200 ⁴³¹,⁴⁴¹. In contrast to cellulose, hemicelluloses are amorphous, often branched, and possess different solution properties, which make them more susceptible to hydrothermal extraction and hydrolysis. They readily dissolve in water at high temperatures, typically ranging from 180 to 230 °C, and under pressures of approximately 1 to 3 MPa ⁴³⁶,⁴⁴²⁻⁴⁴⁴. Hemicelluloses have a low molecular weight, feature a branched polymer topology, and possess chemical substitutions on C2, C3, and C6 positions. These carbohydrate polymers include xylans (such as arabinoxylans and 4-O-methyl-glucuronoxylans), galactomannans, glucomannans, and xyloglucans (4-linked β-D-glucans with attached side chains) ⁴³³. The most common sugar residues in hemicelluloses are D-xylose, D-mannose, D-galactose, D-glucose, L-arabinose, 4-O-methyl-D-glucuronic acid, D-galacturonic acid, and D-glucuronic acid ⁴⁴⁵. Chemical modification of hemicelluloses is less frequently reported compared to cellulose modification due to the inherent heterogeneity of these biopolymers, which complicates specific modification techniques. The variability in hemicellulose structure presents challenges for precise modification. Despite these challenges, ongoing research is focused on optimizing their properties for various industrial applications, capitalizing on their hydrophilicity and susceptibility to hydrolysis for efficient processing ⁴⁴⁶. Hemicelluloses are naturally hydrophilic and can be easily hydrolyzed using diluted acid or alkaline solutions. Xylan, a common type of hemicellulose, is present in various plant biomasses and degrades thermally between 200 and 350°C, releasing gases such as CO, CO₂, CH₄, and H₂O ⁴⁴⁷.

## 2.5.3. Hemicellulose (bio)sensing applications

Hemicelluloses are non-crystalline, branched polymers with low molecular weight, prized for their biodegradability, non-toxicity, and biocompatibility ⁴⁴⁸. Hemicellulose, despite its promising attributes such
1838 as renewability, biocompatibility, and low cost, faces several limitations when used as an electrode
1839 material modifier for sensing applications ⁴²⁴. One major challenge is its inherent structural
1840 heterogeneity and complexity, which can lead to inconsistent performance and difficulties in achieving
1841 uniform modification of electrode surfaces ⁴⁴⁹,⁴⁵⁰. Additionally, hemicellulose exhibits poor electrical
1842 conductivity, which is a critical property for efficient signal transduction in sensors ⁴⁵¹,⁴⁵². Its mechanical
1843 stability is also a concern, as hemicellulose-based materials can be prone to swelling and degradation in
1844 aqueous environments, potentially compromising the durability and reliability of the sensors ⁴⁵³. To
1845 address these limitations, hemicelluloses are frequently combined with other materials to fabricate
1846 electroactive hemicellulose-based composites. By blending hemicelluloses with conductive polymers,
1847 nanoparticles, or carbon-based materials, researchers can significantly enhance their electrochemical
1848 properties and stability ⁴⁵⁰⁻⁴⁵². This composite approach aims to improve the overall performance of the
1849 electrode surfaces by increasing electrical conductivity, mechanical strength, and chemical stability. The
1850 addition of conductive materials helps overcome the inherent low conductivity of hemicelluloses, while
1851 also addressing issues related to moisture sensitivity and thermal degradation ⁴⁵⁰⁻⁴⁵². Such composites
1852 enable more effective and reliable modifications of electrode surfaces, leading to improved sensor
1853 performance and broader application potential in various sensing technologies ¹⁴,⁴⁵¹. Table 4 summarizes
1854 several recent studies that explore the use of hemicellulose-based materials in sensing applications.

1855 The studies summarized in the Table 5 highlight a diverse array of advancements in sensor
1856 technologies using hemicellulose-based materials, each demonstrating unique attributes and potential
1857 applications. A key area of development is in the creation of durable and multifunctional hydrogels. For
1858 instance, nano-polydopamine-reinforced hemicellulose-based hydrogels demonstrated exceptional
1859 mechanical properties, stable electrochemical performance, and strong self-adhesive capabilities, proving
1860 effective as motion sensors and transdermal drug delivery systems ⁴⁵¹. Similarly, MXene-hemicellulose
1861 films were engineered to achieve high electrical conductivity (64 300 S m⁻¹) and mechanical strength
1862 (125 MPa), offering a robust solution for supercapacitors and humidity sensors without compromising
1863 performance ⁴⁵⁴. The multifunctional hybrid hydrogel incorporating hemicellulose-decorated polypyrrole,
1864 polyvinyl alcohol, tannic acid, and polyacrylamide exhibited remarkable transparency, conductivity, and
1865 stretchability, making it suitable for wearable sensors in human motion monitoring ⁴⁵⁵. Additionally,
1866 hemicellulose/polypyrrole composite hydrogels were developed to be stretchable, water-retentive, and
1867 anti-freezing, with enhanced conductivity and mechanical properties, showcasing their potential for
1868 wearable devices and sports monitoring ⁴⁵⁰. Tannic acid-modified hemicellulose nanoparticles and Fe³⁺
1869 were used to create hydrogels with rapid gelation and exceptional mechanical properties, demonstrating
1870 advanced self-healing and adhesion characteristics that improve performance as pressure sensors ⁴⁵².
1871 Another variant, incorporating ionic PAA-TA@HC-Al³⁺ hydrogels, showed high stretchability, toughness,
1872 and self-recovery, with strong self-adhesion and additional protective properties, making it effective for
1873 detecting various movements ¹⁷. Hemicellulose-derived ratiometric fluorescent aerogels exhibited ultra-
1874 trace level detection capabilities for arsenite ions and ciprofloxacin, with high adsorption capacities,
1875 indicating their potential for environmental monitoring and contamination remediation ⁴⁵⁶. Lastly, carbon
1876 electrodes derived from hemicellulose-based Arenga pinnata bunches demonstrated enhanced
1877 supercapacitor performance with optimal surface morphology and high specific surface area, presenting
1878 a promising alternative for electrode materials ⁴⁵⁷. Xylan hemicellulose-based conductive hydrogels, with
1879 MXene incorporated, displayed high tensile strength and extreme stretchability, indicating their potential
1880 for use in stretchable and tough conductive materials ⁴⁵⁸.
<table><caption>1881 Table 5: Advancements in hemicellulose-based sensor technologies: performance metrics and applications across diverse platforms</caption><thead><tr><td>Electrode materials</td><td>Analytes/parameters measured</td><td>Main results achieved</td><td>Ref.</td></tr></thead><tbody><tr><td>Nano-polydopamine-reinforced hemicellulose-based hydrogels</td><td>Body movements (e.g., throat vibrations)</td><td><ul><li>The hydrogels demonstrated excellent mechanical properties, stable electrochemical performance, and strong self-adhesive capabilities.</li><li>They withstood 1000 compression cycles without significant damage, had a tensile strain of 101%, and showed superior adhesion to skin compared to fibrin glue.</li><li>The hydrogels also served as effective motion sensors and drug patches for transdermal drug delivery.</li></ul></td><td>451</td></tr><tr><td>MXene-hemicellulose films</td><td>------------</td><td><ul><li>MXene-hemicellulose films were developed with high electrical conductivity (64,300 S m<sup>-1</sup>) and mechanical strength (125 MPa), making them suitable as high-performance electrode materials for supercapacitors and humidity sensors.</li><li>The approach enhances mechanical properties without compromising conductivity, offering a robust solution for multifunctional applications.</li></ul></td><td>454</td></tr><tr><td>Multifunctional hybrid hydrogel incorporating hemicellulose-decorated polypyrrole (H/PPY), polyvinyl alcohol (PVA), tannic acid (TA), and polyacrylamide (PAM).</td><td>Strain signals of index finger and elbow flexion, pulse beat.</td><td><ul><li>The hybrid hydrogel exhibited high transparency (79.6% at 2 mm thickness), conductivity (3.12 S/m), mechanical strength (325.4 kPa), and stretchability (1497.2%).</li><li>It demonstrated effective strain and pulse monitoring capabilities and good adhesion to various substrates, including human skin.</li><li>The hydrogel improved properties make it suitable for wearable sensors in human motion monitoring.</li></ul></td><td>455</td></tr><tr><td>Hemicellulose/polypyrrole (H/PPY) composite hydrogels.</td><td>Human motion signals (finger bending, wrist bending, throat deformation).</td><td><ul><li>The study developed stretchable, water-retentive, and anti-freezing H/PPY hydrogels for epidermal strain sensors.</li><li>The hydrogels demonstrated enhanced conductivity (from 2.1 to 5.1 S/m), reduced freezing/thawing temperatures (-43.1°C and -22.1°C), and impressive mechanical properties including high tensile strain (1094.9%), compressive strength (1790.2 kPa), and toughness (2.82 MJ/m<sup>3</sup>).</li><li>The sensors showed excellent remoldability and durability, with good performance after 250 cycles and effective detection of various human motions.</li><li>These hydrogels are promising for applications in wearable devices, sports monitoring, medical monitoring, and soft robotics.</li></ul></td><td>450</td></tr><tr><td>Tannic acid-modified hemicellulose nanoparticles (TA@HC) and Fe<sup>3+</sup> were utilized to prepare PAA/TA@HC/Fe<sup>3+</sup> hydrogels. Incorporating TA@HC and Fe<sup>3+</sup> into the sodium persulfate (SPS) and acrylic acid (AA) polymerization system led to the formation of these hydrogels.</td><td>Human movements, pressure</td><td><ul><li>PAA/TA@HC/Fe<sup>3+</sup> hydrogels were developed with rapid gelation (within 30 seconds at room temperature) due to the dynamic catechol (TA) and Fe<sup>3+</sup> redox system.</li><li>The hydrogels exhibited exceptional mechanical properties, including a high tensile strain of up to 5600%, and enhanced self-healing and adhesion.</li><li>The asymmetric adhesive design, with a nonadhesive upper surface and adhesive bottom surface, improved the hydrogel performance as a pressure sensor and its resistance to interference from pollutants.</li><li>The hydrogels demonstrated ionic conductivity, self-healing, adhesiveness, and anti-ultraviolet transmission properties, making them effective for wearable sensors and strain monitoring.</li></ul></td><td>452</td></tr></tbody></table>
<table><tr><td>Tannic acid modified hemicellulose nanoparticles (TA@HC) embedded in ionic PAA-TA@HC-Al<sup>3+</sup> hydrogels.</td><td>Strain, pulse, and breathing movements.</td><td><ul><li>The ionic hydrogel demonstrated exceptional stretchability (1060%), toughness (1.52 MJ/m<sup>3</sup>) and self-recovery (87%).</li><li>It offered strong self-adhesion, anti-ultraviolet, anti-oxidative, and antibacterial properties.</li><li>As a wearable strain sensor, it accurately detected and differentiated large and micro movements, including weak pulses and breathing.</li></ul></td><td>17</td></tr><tr><td>Hemicellulose-derived ratiometric fluorescent aerogel</td><td>Arsenite ions (As (III)) and ciprofloxacin (CPR) antibiotic</td><td><ul><li>The hemicellulose-based fluorescent aerogel, fabricated from oxidized rice straw and crosslinked with chitosan, demonstrated ultra-trace level detection of As (III) with a limit of 3.529 pM and CPR with a limit of 55.2 nM.</li><li>The aerogel also showed high adsorption capacities of 185 µg/g for As (III) and 454 mg/g for CPR.</li><li>It was applied to real water samples, proving its potential for effective remediation of these contaminants.</li></ul></td><td>456</td></tr><tr><td>Carbon electrodes derived from hemicellulose-based Arenga pinnata bunches (APB) through carbonization at temperatures of 650 °C, 700 °C, 750 °C, and 800 °C.</td><td>Supercapacitor performance metrics</td><td><ul><li>The study highlighted that carbonization at 700 °C (APB-700) yielded electrodes with optimal surface morphology featuring a combination of nanofibers and micro- to mesopores.</li><li>This configuration achieved a specific surface area of 1231.896 m<sup>2</sup>/g, specific capacitance of 201.6 F/g, energy density of 28.0 Wh/kg, and power density of 109.5 W/kg, enhancing supercapacitor performance.</li><li>These carbon nanofibers from Arenga pinnata bunches offered promising potential as free-standing electrode materials without the need for additional doping, binders, or electrospinning methods.</li></ul></td><td>457</td></tr><tr><td>Stretchable and tough xylan hemicellulose-based conductive hydrogels, with MXene incorporated as conductive fillers.</td><td>Strain and movement in human motion</td><td><ul><li>Xylan-based hydrogels were fabricated with high tensile strength (0.34 MPa), extreme stretchability (2098.4%), and notable toughness (3.79 ± 0.95 MJ/m<sup>3</sup>).</li><li>Incorporating MXene improved these properties further to 0.51 MPa tensile strength and 5.95 ± 1.19 MJ/m<sup>3</sup> toughness.</li><li>The hydrogels demonstrated reliable sensitivity as strain sensors for monitoring human movements, showcasing their potential for use in stretchable and tough conductive materials, especially with the inclusion of renewable xylan and bio-based resources.</li></ul></td><td>458</td></tr></table>
Several research studies have explored hemicellulose-derived biomass composites for sensing applications, with promising results<sup>450,455,459</sup>.

**Wearable sensors.** In wearable sensor applications, smart functional fillers, such as plant-derived hemicellulose, can significantly enhance the mechanical properties of ionic hydrogels. Tannic acid-modified hemicellulose nanoparticles (TA@HC) and Fe³⁺ were incorporated into PAA hydrogels, accelerating gelation within 30 s at room temperature<sup>452</sup>. The TA and Fe³⁺ system activated sodium persulfate (SPS), generating hydroxyl radicals that facilitated rapid gelation. The resulting PAA/TA@HC/Fe³⁺ hydrogel exhibited exceptional mechanical strength (up to 5600% strain), adhesiveness, rapid self-healing, and reproducible adhesion to various substrates<sup>452</sup>. By selectively coating Fe³⁺ on the upper surface, an asymmetric adhesive hydrogel was created, allowing for comfortable skin contact while repelling pollutants, making it an effective pressure sensor<sup>452</sup>.

**Humidity sensors.** Rao et al.<sup>14</sup> recently developed hemicellulose films with enhanced mechanical properties by incorporating graphene oxide in hemicellulose matrix for humidity sensing. The resulting composite film demonstrated a high tensile strength of 43.83 MPa and exhibited high sensitivity to humidity, with a significant change in the storage modulus of the hybrid films at different humidity levels<sup>14</sup>.

**Supercapacitors.** Falco et al.<sup>460</sup> demonstrated the effective utilization of hemicellulose derived from acid pretreatment of biomass products as a precursor for the synthesis of functional carbon materials, which were employed as electrode materials for supercapacitors. The resulting activated carbons exhibited favorable textural properties and delivered promising results, with a specific capacitance of 300 F g<sup>-1</sup> at 250 mAg<sup>-1</sup> <sup>460</sup>. In addition, Lin et al.<sup>461</sup> utilized hemicellulose as a precursor to fabricate porous activated carbon for high-performance supercapacitors. The hemicellulose-derived porous activated carbon exhibited an impressive specific capacitance of 302.4 F g<sup>-1</sup> at a current density of 0.5 A g<sup>-1</sup>. The supercapacitor demonstrated energy and power density values of 11.7 Wh kg<sup>-1</sup> and 349.9 W kg<sup>-1</sup>, respectively<sup>461</sup>. These findings highlight the potential of hemicellulose-based materials for diverse sensing and energy storage applications.

**Chemical and environmental sensing.** Jiang et al.<sup>462</sup> synthesized a hybrid material consisting of hemicellulose, nitrogen-rich deep eutectic solvent, and carbon quantum dots for ultrasensitive detection of silver ions and L-cysteine, employing an "off-on" sensing pattern<sup>462</sup>. This probe exhibited high selectivity towards silver ions, achieving a low detection limit of 21 nM. The same composite film was successfully utilized for detecting L-cysteine in a dynamic range of 0-100 µM, with a detection limit of 242 nM<sup>462</sup>. Furthermore, Yang et al.<sup>463</sup> employed a microwave-assisted synthesis method to produce xylan-derived carbon quantum dots for tetracycline sensing. Under optimized conditions, a novel sensing platform capable of detecting tetracycline in a linear range of 0.05-20 µM was established, with a detection limit of 6.49 nM<sup>463</sup>. In a similar study, polyamine-functionalized carbon dots derived from xylan were investigated for the detection of tannic acid<sup>464</sup>. This research established an acid detection platform using hybrid materials in both water and ethanol solutions. The dynamic range for tannic acid detection ranged from 0.1 to 5 µM, with detection limits of 36.8 nM and 44.9 nM determined for water and ethanol solutions, respectively<sup>464</sup>. Furthermore, Dammak et al.<sup>465</sup> combined cellulose nanocrystals and xylans to develop multilayer thin films suitable for detecting xylanase activity. These films demonstrated sensitivity to xylanase action, with the sensitivity of the test evaluated in comparison to a conventional colorimetric measurement method, which relies on the detection of reducing sugars released through enzymatic hydrolysis<sup>465</sup>. In addition, hemicellulose-based sensors also hold promise for environmental applications.
For example, Helim et al. ⁴⁵⁹ developed a sensor using hemicellulose (HEM) extracted from Opuntia Ficus Indica cactus and agarose (AG), creating a sensitive layer on a gold electrode (Figure 26A). Cyclic voltammetry (CV) (Figure 26B) was employed to evaluate the sensor's electrochemical behavior and electron transfer kinetics using [Fe(CN)₆]³⁻/₄⁻. The functionalized gold electrodes (AG and AG/HEM) exhibited decreased current and shifted potential. Kinetic characterization via CV indicated diffusion-controlled redox processes ⁴⁵⁹. Electrochemical impedance spectroscopy (EIS) (Figure 26C) confirmed increased charge transfer resistance post-modification, aligning with CV results. Detection of lead ions (Pb²⁺) showed a decrease in charge transfer resistance, as positively charged ions facilitated redox marker transfer ⁴⁵⁹. In this study, the functional groups of hemicellulose to form complexes with metal ions and leveraged agarose gelling properties for membrane stability. It demonstrated a high affinity for Pb²⁺ due to the chemical structure of hemicellulose, outperforming detection for Hg²⁺, Ni²⁺, and Cu²⁺. Square wave voltammetry revealed a detection limit of 1.3 fM for Pb²⁺. Application of the sensor in river and sea water using the standard addition method confirmed its efficacy in lead detection (Figure 26D) ⁴⁵⁹.

<figure><img src="image_48.png" /><figcaption>**Figure 26:** (A) Schematic of gold sensor modified with biopolymers AG-HEM for lead ion detection (Au: Gold, AG: Agarose, HEM: Hemicellulose). (B) (a) Cyclic voltammograms of bare electrode (solid line), Au modified with AG (dashed line), and Au-AG-HEM (dotted line) in 5 mM [Fe(CN)₆]³⁻/₄⁻ at 80 mV s⁻¹ scan rate; (b) Cyclic voltammograms of Au-AG-HEM at different scan rates in the same solution. (C) Nyquist plots of post gold electrode modifications with AG and AG/HEM (A) and after lead ion detection at 1 µM concentration (B). Measurements conducted in [Fe(CN)₆]³⁻/₄⁻ solution, frequency range 0.1 Hz to 100 kHz, DC potential 10 mV, and applied potential 0.2 V. (D) (a) Square wave voltammetry (SWV) for Pb²⁺ determination in river water after successive Pb²⁺ additions; (b) Corresponding calibration curve. Reproduced with permission from Ref. ⁴⁵⁹, Copyright © 2023 Elsevier.</figcaption></figure>

**Medical sensing.** In the medical sector, hemicellulose-based hydrogels with advanced mechanical and electrochemical properties have been developed for sensing applications. A recent study introduced nano-polydopamine-reinforced hemicellulose-based hydrogels with multistage pore structures (Figure 27A), which maintained stable mechanical properties even after 1,000 cyclic compressions. The hydrogel exhibited an ultimate tensile strain of 101%, surpassing that of native skin ⁴⁵¹. With a shear adhesion strength of 7.52 kPa to skin tissue, it outperformed fibrin glue (Greenplast). The addition of nano-
polydopamine enhanced electrical conductivity and reduced impedance. The nanocomposite hydrogel demonstrated exceptional mechanical strength, stable electrical conductivity, and self-adhesive characteristics. It also exhibited motion-sensing capabilities, with a gauge factor (GF) of approximately 1.04 and a response time of 150 ms <sup>451</sup>. The hydrogel-based sensor accurately monitored various movements, such as finger, wrist, and elbow bending, with distinct resistance variations (Figure 27B). It showed frequency-independent behavior and dynamic stability during knee bending, indicating its potential for limb control and healthcare applications, including monitoring swallowing disorders (Figure 27C). This multifunctional hydrogel acts as a real-time motion sensor, cationic drug carrier, and electrically stimulated drug patch, offering promising implications for next-generation flexible materials in health monitoring and self-administration <sup>451</sup>.

<figure><img src="image_49.png" /></figure>

<figure><img src="image_50.png" /></figure>

<figure><img src="image_51.png" /></figure>

<figure><img src="image_52.png" /><figcaption>**Figure 27:** (A) Schematic representation of the conductive, self-adhesive, and compressive hydrogel with internal cross-linking. (B) Real-time monitoring of various human movements with sensors attached to different body parts: (a) finger, (b) wrist, (c, d) elbow, (e) knee joint, and (f) throat. (C) Schematic diagram illustrating the self-powered transdermal drug delivery (TDD) closed-loop therapy system, along with characterization of triboelectric nanogenerator (TENG) and cross-sectional histological images of skin after rhodamine 6G (R6G) delivery from a patch for 6 hours: (a) TENG and TDD closed-loop therapy system illustration, (b) Experimental setup mimicking human motion-driven TDD using a linear motor, (c–e) Open-circuit voltage (VOC), short-circuit current (Isc), and transferred charge (Qsc) of the TENG, (f) Placement of drug-loaded hydrogel patch on the positive electrode, (g) Skin under natural conditions (without TENG connection). Scale bar: 100 µm. Reproduced with permission from Ref. <sup>451</sup>, Copyright © 2023 American Chemical Society.</figcaption></figure>
Moreover, renewable resource-based hydrogels, such as those derived from hemicellulose, are promising for soft devices and wearables due to their softness and electrical conductivity. However, traditional hemicellulose hydrogels face challenges such as poor conductivity and freezing issues. Recent research addressed these limitations by dissolving hemicellulose in deep eutectic solvents (DES), made from choline chloride and imidazole⁴⁶⁶. The resulting DES hydrogels were formed through photo-initiated reactions with acrylamide and N,N'-Methylenebisacrylamide as a crosslinker. These hydrogels demonstrated high electrical conductivity (2.13 S/m at room temperature and 1.97 S/m at -29 °C) and anti-freezing properties (freezing point: -47.78 °C). They also functioned effectively as strain sensors for monitoring human activities⁴⁶⁶. Additionally, hemicelluloses are frequently blended with other materials to enhance their properties for specific sensing applications. For instance, MXene-based materials were valued for their mechanical robustness and electrical conductivity in multifunctional uses⁴⁵⁴. While adding macromolecular polymers mitigates mechanical brittleness in MXene films, it often reduces electrical conductivity. Chen et al.⁴⁵⁴ developed bioinspired MXene-hemicellulose composite films that maintain high electrical conductivity and mechanical strength. Short-chained hemicellulose, inspired by wood, acted as a molecular binder, improving mechanical properties without introducing insulating phases. These composite films exhibited high electrical conductivity (64 300 S/m) and mechanical strength (125 MPa), making them suitable for supercapacitors and humidity sensors. This study proposed an alternative method for producing robust MXene-based materials, highlighting hemicellulose role as a molecular binder in the composites⁴⁵⁴.

**Challenges and opportunities in hemicellulose-based sensors.** Hemicellulose, derived from Lignocellulosic biomass, exhibits significant potential in sensing applications due to its biocompatibility, renewable nature, and ability to form mechanically robust films. However, one of the primary challenges associated with hemicellulose-based sensors is the variability in the composition and structure of hemicellulose, which depends heavily on the source material and the extraction method employed. This variability can lead to inconsistencies in sensor performance and reproducibility. The composition of hemicellulose can vary widely between different plant species and even within different parts of the same plant, affecting its chemical properties and interaction with other materials. This inconsistency complicates the standardization of sensor fabrication processes, making it difficult to achieve reliable and accurate sensor performance across different batches and applications. In addition, while hemicellulose-based sensors have demonstrated potential in detecting a range of analytes, including heavy metals, gases, and biomolecules, several issues need to be addressed to enhance their practical utility. Specifically, the sensitivity, selectivity, and response time of these sensors may not always align with the stringent requirements of practical applications. For instance, while hemicellulose-based sensors can detect various target substances, their ability to distinguish between closely related analytes or to operate efficiently under varying environmental conditions can be limited. Improving these aspects requires a deeper understanding of how hemicellulose interacts with different analytes and the development of strategies to enhance its responsiveness and specificity. Furthermore, another significant challenge is the long-term stability and durability of hemicellulose-based sensors. These sensors may degrade over time or under harsh environmental conditions, such as extreme temperatures, high humidity, or exposure to corrosive substances. The degradation of hemicellulose can affect the structural integrity of the sensors and lead to a loss of functionality, thereby compromising their reliability for continuous monitoring applications. Addressing this issue involves developing methods to enhance the stability of hemicellulose-based sensors, such as incorporating protective coatings or modifying the hemicellulose structure to
2017 improve its resilience. Despite these challenges, there are promising opportunities for advancing
2018 hemicellulose-based sensors. Ongoing research is focused on optimizing hemicellulose extraction
2019 methods to produce more consistent and high-quality materials. Efforts are also being made to modify
2020 the chemical structure of hemicellulose to improve its performance and compatibility with other materials.
2021 Additionally, integrating hemicellulose with other substances, such as conductive polymers or
2022 nanomaterials, can enhance its sensing capabilities and overall performance. These advancements hold
2023 the potential to overcome current limitations and unlock the full potential of hemicellulose-based sensors
2024 for a wide range of applications.

2025 **2.6. Lignin and its applications in (bio)sensors**

2026 **2.6.1. Lignin characteristics and extraction**

2027 Lignin, a complex class of organic polymers, is a fundamental structural component in the support
2028 tissues of vascular plants and certain algae, providing rigidity and resistance to decay, particularly in
2029 woody plants. Chemically, lignins consist of cross-linked phenolic polymers and are one of the most
2030 abundant renewable biopolymers on Earth, representing approximately 40% of total biomass 55,467.
2031 Structurally, lignin is a three-dimensional polymer composed of phenylpropane units localized primarily
2032 in the cell walls of plants. Its building blocks are derived from three aromatic alcohol precursors: p-
2033 coumaryl, coniferyl, and sinapyl alcohols, which form phenolic subunits known as p-hydroxyphenyl (H),
2034 guaiacyl (G), and syringyl (S) moieties 468. Gymnosperms primarily contain G units, dicotyledonous
2035 angiosperms have a mix of G and S units, and monocotyledonous plants contain all three moieties 469.
2036 The structure of lignin includes various types of bonds, such as β-O-4, β-5, β-β, and 5-5 linkages,
2037 contributing to its rigidity and resistance to degradation. Its high degree of aromaticity makes it resistant
2038 to chemical and biological breakdown. Lignin serves as a natural defense mechanism for plants, aiding in
2039 structural support, water and nutrient transport, and protection against parasitic attacks and other threats
2040 470. The structural composition of lignin is illustrated in Figure 28. The properties of lignin vary depending
2041 on botanical origin, extraction method, and processing conditions, with hardwood lignin typically having
2042 a higher syringyl (S) to guaiacyl (G) ratio compared to softwood lignin.
<figure><img src="image_53.png" /><figcaption>**Figure 28:** Overview of lignin structure. Highlighted are sinapyl alcohol and coniferyl alcohol, the primary monomers, indicating reacting carbons with C–O or C–C bonds. A hypothetical lignin structure depicts these bonds, along with calculated S/G ratio, β-O-4 content, and monomer yield. Reproduced with permission from Ref. ⁴⁷¹, Copyright © 2019 Springer Nature.</figcaption></figure>

Lignin extraction from Lignocellulosic biomass is essential for biofuel production, chemical synthesis, and materials science ⁴⁶⁹. Lignin, a complex aromatic polymer, provides structural support to plants but is challenging to process due to its recalcitrance and insolubility in most solvents ²¹²,⁴⁶⁹. Efficient extraction methods are required to isolate lignin while preserving its chemical structure for downstream applications. Several methods have been developed to extract lignin, each with its own advantages and limitations.

**Acid Hydrolysis:** This method involves the treatment of Lignocellulosic biomass with strong and organic acids in combinaison with other chemicals at high temperatures ⁴⁷²,⁴⁷³. The acid hydrolyzes hemicellulose and breaks lignin-carbohydrate bonds, dissolving lignin in the acidic solution. The process is followed by neutralization and precipitation to recover lignin in solid form. Careful control is required to prevent degradation and the generation of inhibitors that may interfere with downstream processes ⁴⁷²,⁴⁷³. In the study conducted by Watkins et al. ⁴⁷³, the extraction of lignin was achieved using an acid hydrolysis process, involving formic acid and peroxyformic acid treatments. Biomass was pulped, treated with these acids, and then bleached to remove impurities. The resulting lignin was purified and analyzed, revealing that lignin from alfalfa had the highest yield and specific thermal properties ⁴⁷³. In another study, poplar wood was fractionated using aqueous solutions of p-toluenesulfonic acid (p-TsOH) at temperatures below 98 °C. Acid hydrolysis solubilized up to approximately 80% of lignin, which contained high β-aryl-ether linkages and low condensation, facilitating a lignin monomer yield of over 30% ⁴⁷². Gel-permeation chromatography and differential scanning calorimetry showed that the lignins had high molecular weights and low glass transition temperatures. This process preserved cellulose and solubilized up to 90% of xylan, offering promising yields and applications ⁴⁷².
2068

2069

2070

2071

2072

2073

2074

2075

2076

2077

2078

2079

2080

2081

2082

2083

2084

2085

**Alkali Pretreatment:** In this method, Lignocellulosic biomass are treated with strong alkaline solutions such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). This disrupts ester bonds and ether linkages within lignin, leading to its solubilization in the alkaline solution 474,475. Alkali pretreatment also removes hemicellulose, enhancing cellulose accessibility for enzymatic hydrolysis. Advantages include high lignin yield and minimal solvent usage. However, it requires high energy input, can degrade lignin, and generates large amounts of wastewater. For instance, *Saccharum ravannae*, an elephant grass was used to extract high-purity alkaline lignin through KOH-mediated alkaline hydrothermal pretreatment using the oil bath process 474. The extraction was optimized by varying KOH concentration (1-3%), reaction time (50-200 min), and solid loading (5-15%) using response surface methodology. At optimal conditions (2.4% KOH, 6.41% solid loading, 176.57 min), lignin recovery reached 15.81 ± 0.32 g/100 g, with 93.7% purity achieved under different conditions 474. In another work, NaOH was employed to pretreat the biomass for extraction of lignin and further biogas production. The NaOH pretreatment of rice straw (biomass) aimed to improve the economic efficiency of biomethane production through anaerobic digestion 475. A 5% NaOH solution was used to treat rice straw at 121°C for 20 min, removing 73.6% of lignin. The NaOH black liquor was filtered and recycled, with the second cycle reducing lignin content by 55.5%. The treated straw produced 1452.4 mL/gVS of biogas, significantly more than untreated straw. The recycling of NaOH proved effective for lignin removal and methane production while reducing environmental impact 475.

2086

2087

2088

2089

2090

2091

2092

2093

2094

2095

2096

2097

2098

2099

2100

**Organosolv Fractionation:** This method uses a solvent mixture containing organic solvents (e.g., ethanol, methanol, or acetone) and water under elevated temperatures. The solvent disrupts the lignin structure, causing it to dissolve along with other extractives, leaving cellulose and hemicellulose as solid residues 476,477. Organosolv fractionation produces lignin with higher purity and less chemical modification, making it suitable for various applications 476,477. In a research study, the organosolv process was optimized to extract lignin from black spruce (Picea mariana), achieving a high yield while preserving solid cellulose recovery 476. The process utilized 70% ethanol liquor at a 1:10 wood-to-liquor ratio and 5% $FeCl_3 \cdot 6H_2O$ as a catalyst, treated in a Parr reactor at 180 °C for 90 minutes. This method yielded a total lignin recovery of 74% with 97% purity, the highest reported for softwoods. A secondary, denser lignin was also obtained 476. Another study demonstrated the effectiveness of mild alcohol-based organosolv fractionation using walnut shells as precursor biomass for lignin extraction. This method preserved the β-aryl ether (β-O-4) content while improving lignin solubility by incorporating alcohol at the benzylic α-position 477. The process involved heating a mixture of walnut shells, alcohol, water, and HCl, then filtering and concentrating the extract to obtain organosolv lignin. The study revealed that α-substitution significantly enhanced extraction efficiency and lignin quality 477.

2101

2102

2103

2104

2105

2106

2107

2108

2109

2110

**Emerging Technologies:** Ionic liquids (ILs) and deep eutectic solvents (DES) are emerging as promising alternatives for lignin dissolution and separation due to their distinct physicochemical properties 478. Ionic liquids, which are salts in liquid form at relatively low temperatures, possess unique features such as low volatility, tunable solvation capabilities, and high thermal stability 478,479. These properties make them highly effective for disrupting the complex structure of lignin, facilitating its dissolution without the need for harsh chemicals or extreme conditions. The principle behind their effectiveness lies in their ability to break hydrogen bonds and interact with the aromatic and hydrophobic components of lignin 478,479. On the other hand, deep eutectic solvents, formed by combining a hydrogen bond donor and a hydrogen bond acceptor, share many of the advantages of ILs, such as low toxicity and environmental friendliness. They operate by similarly disrupting lignin intermolecular bonds, enabling
efficient separation<sup>478,480</sup>. Despite these advantages, both ILs and DES face challenges that limit their
scalability and industrial application. High production costs of ionic liquids, complex recycling processes,
and the need for large-scale optimization of both techniques present significant economic and technical
barriers. Moreover, the precise tailoring of these solvents for different types of lignin and biomass sources
is still an ongoing area of research, which adds to the complexity of their broader adoption<sup>478-480</sup>.

*Steam Explosion:* Particularly suited for woody biomass, this process involves high-pressure steam treatment followed by rapid depressurization. The lignocellulosic structure undergoes physical and chemical changes, making lignin more accessible and facilitating its separation from cellulose and hemicellulose. Steam explosion also enhances the enzymatic digestibility of cellulose, making it attractive for biofuel production <sup>481</sup>. A one-pot method was proposed to extract and chemically modify lignin from pre-treated Phragmites australis lignocellulosic biomass. The biomass was initially pre-treated by steam explosion at two severity levels <sup>482</sup>. Lignin was extracted using a microwave-assisted organosolv method with γ-valerolactone as the solvent. The most severe steam explosion condition achieved a 78% delignification. The process yielded nearly pure lignin, which was then chemically modified in the extraction solution. This method demonstrated a high-yield, cleaner approach for obtaining and modifying lignin <sup>482</sup>. In another study, steam explosion was combined with an enzymatic/acid method to extract lignin from a specific biomass. Corncob residue after acid-catalyzed steam explosion (CRSE) was found to be rich in cellulose and lignin <sup>483</sup>. An enzymatic mild acidolysis lignin (EMAL) extraction was applied to the CRSE, with modified conditions to enhance lignin recovery and purity. The optimal conditions produced lignin with 99.0% purity and a 57.3% yield. Comparative studies showed that CRSE EMAL had a higher molecular weight and better antioxidant activity (IC50 = 128 µg/mL) compared to untreated corncob lignin <sup>483</sup>.

*Supercritical Fluid Extraction (SFE):* This innovative approach uses supercritical fluids like carbon dioxide (CO₂) to selectively dissolve lignin. SFE offers advantages such as tunable selectivity and minimal solvent usage, but requires specialized equipment and operating conditions, increasing capital investment and operational complexity <sup>484,485</sup>. In a recent study, Ignin as a valuable source of low molecular weight compounds, was extracted from softwood and hardwood chips using Supercritical Fluid Extraction (SFE) and CO₂-expanded liquid extraction (CXLE) <sup>484</sup>. Ethanol, acetone, and ethyl lactate were tested as green co-solvents. The study found that ethyl lactate and acetone yielded the highest amounts of extractable lignin. The optimal extraction used a CO₂/acetone/water mixture at 60 °C and 350 bar, successfully detecting 13 lignin monomers and 6 dimers, showcasing SFE effectiveness <sup>484</sup>. Additionally, the study conducted by Seo et al. <sup>485</sup> aimed to extract lignin using Supercritical Fluid Extraction (SFE) from hardwood (*Quercus mongolica*) treated with supercritical water (SCW) oxidation. The crude supercritical lignin (SCL) was fractionated sequentially with four organic solvents, yielding five fractions (F1–F4 and FIN) <sup>485</sup>. As fractionation progressed, the molecular weight (MW) of the lignins increased, while the content of methoxyl and phenolic hydroxyl groups decreased. The syringyl/guaiacyl ratio (S/G ratio) rose with MW, thermal stability decreased, and the glass transition temperature (Tg) increased from 83 °C to 137 °C <sup>485</sup>.

*Biological Methods:* Enzymatic delignification uses lignin-degrading enzymes (e.g., lignin peroxidase and manganese peroxidase) produced by microorganisms or genetically engineered organisms to selectively remove lignin <sup>486</sup>. These enzymes break lignin into smaller, soluble fragments that can be easily separated from cellulose and hemicellulose. Enzymatic processes offer mild reaction conditions, high specificity, and minimal environmental impact, but they often have slower reaction rates and higher costs associated with enzyme production and purification <sup>486</sup>. In the study performed by Zhang
et al. ⁴⁸⁶, lignin with high purity and structural integrity was isolated from enzymatic residue of corn stover. The research investigated the degradation of lignin using laccase, lignin peroxidase, and manganese peroxidase ⁴⁸⁶. Structural changes post-degradation were characterized by scanning electron microscopy, nitrogen adsorption, and Fourier transform infrared spectroscopy, while enzymatic products were analyzed by gas chromatography-mass spectrometry ⁴⁸⁶. The highest degradation rate of 25.79% was achieved with a mixture of all three enzymes, which disrupted lignin macromolecular structure and broke key chemical bonds, leading to the formation of more acidic compounds. The study highlighted the synergistic use of these enzymes for lignin biodegradation ⁴⁸⁶. In addition to enzymatic methods, microbial approaches can also be employed to depolymerize lignin and disrupt its chemical structure. Chang et al. ⁴⁸⁷ explored the extraction of lignin from waste rice straw using a microbial electro-Fenton process in a microbial peroxide-producing cell (MPPC). This method aimed to address two critical issues: converting waste into valuable products and managing wastewater. The MPPC generated electrochemical voltages of 0.171 ± 0.05–0.497 ± 0.2 V, producing 9 ± 0.43–34 ± 0.11 mM of H₂O₂, which was used to depolymerize lignin at various concentrations ⁴⁸⁷. The study found a direct correlation between lignin depolymerization and H₂O₂ concentration, with Fourier-transform infrared spectroscopy confirming consistent disruption of the lignin structure. The depolymerized lignin contained valuable compounds like carboxylic acid derivatives and benzopyran. SEM analysis showed morphological changes in lignin due to hydroxyl radicals. The process also achieved 60 ± 3–85 ± 1% removal of biochemical and chemical oxygen demand in wastewater treatment, offering a sustainable approach for lignin valorization and wastewater management ⁴⁸⁷.

Regardless of the method used, recovered lignin typically requires further purification and modification to meet specific application requirements. Purification steps may involve precipitation, filtration, or solvent evaporation. Lignin modification processes, such as oxidation, sulfonation, or esterification, tailor its properties for use as a bio-based polymer, dispersant, adhesive, or antioxidant.

Different extraction methods have been used in the literature to extract lignin from Lignocellulosic biomass. Several studies related to the isolation of lignin from biomass, along with key findings, are reported in Table 6. The research studies highlighted in the Table 6 collectively reveal diverse methodologies and outcomes in the extraction and characterization of lignin from various biomass sources, illustrating both advances in extractions techniques and variations in lignin properties. The comparative analysis of extraction methods such as multi-step organic acid treatments ⁴⁷³, ionic liquids (ILs) ⁸⁹, and deep eutectic solvents (DES) ⁴⁸⁰ across different biomass sources ranging from non-wood materials like wheat straw ⁴⁷³ and rice husks ⁹¹ to specialized types such as Eucalyptus urophylla ⁹⁰ and Ocote pine ⁴⁸⁸ demonstrates significant differences in yield, thermal stability, and structural characteristics of the extracted lignin. For instance, the multi-step process involving formic and acetic acids followed by peroxyacetic acid yields lignin with varying thermal stabilities, with wheat straw lignin exhibiting the highest thermal stability ⁴⁷³. In contrast, the use of ILs such as [C2C1 im][OAc] for Eucalyptus ⁹⁰ and nitrile-based ILs for bamboo ⁴⁸⁹ achieved high lignin yields but with significant differences in molecular weight and structural preservation. Similarly, DES methods revealed that different solvent combinations affect molecular weight and heating value, with some DES combinations producing lignins with promising properties for high-energy applications ⁴⁸⁰. The application of novel solvents like NADES ⁴⁹⁰ for kenaf fiber and protic ILs ⁹¹ for wheat straw and rice husks further highlights the adaptability and efficiency of modern extraction techniques, often achieving high yields and preserving valuable lignin structures. However,
2196

each method exhibits specific strengths and weaknesses: while some processes excel in yield, others offer superior structural preservation or thermal stability.

2197

2198

In the reviewed studies, various biomass sources and extraction methods have been employed to obtain and characterize lignin, revealing distinct properties and applications. Non-wood cellulosic biomass, including wheat straw, pine straw, alfalfa, kenaf, and flax fiber, was subjected to a multi-step extraction involving pulping with an 85% organic acid mixture, followed by delignification with PFA/PAA, resulting in varying thermal stabilities and enthalpy measurements <sup>473</sup>. The analysis of Typha capensis lignin extracted using different methods, such as milling, ionic liquid, and ethanol organosolv, highlighted the influence of extraction techniques on acetyl content and polysaccharide hydrolysis, with the milling method retaining the highest acetyl content <sup>89</sup>. Ionic liquid-based microwave-assisted extraction from Eucalyptus urophylla yielded lignin with a broad range of molecular weights and varied thermal stabilities, with significant β-O-4 linkage degradation noted <sup>90</sup>. Oil palm biomass extracted using Pyridinium Formate (PyFor) achieved high lignin extraction efficiencies and demonstrated significant activation energies, with FTIR and NMR analyses confirming the sustainability of the solvent and efficiency of the process <sup>491</sup>. Sugarcane bagasse lignin, extracted via alkaline, ethanol organosolv, and hydrotropic methods, exhibited different carbon contents and heating values, with FTIR showing the highest aromatic and phenolic group presence in hydrotropic-extracted lignin <sup>492</sup>. Etek lignin underwent fast pyrolysis, resulting in varied heating values and functional group distributions, with different molecular weight profiles observed in the methanol-insoluble fraction <sup>493</sup>. The use of deep eutectic solvents (DES) for food processing residues produced lignins with different molecular weights and heating values, with acetic acid chloride (AACC) showing superior properties for certain biomasses <sup>480</sup>. Nitrile-based ionic liquids were effective for bamboo biomass, extracting up to 53% lignin while maintaining cellulose crystallinity and demonstrating the recyclability of the ILs <sup>489</sup>. Deep eutectic solvents (DES) for softwood and brewer's spent grains yielded lignin with varied β-O-4 linkages and molecular weight distributions, showing DES effectiveness at higher temperatures <sup>494</sup>. Finally, the extraction of lignin from poplar species using various organic solvent mixtures revealed differences in lignin yield and structure preservation, with methanol showing the best preservation of monomeric phenolic products and unique substitution patterns <sup>495</sup>. Each extraction method significantly impacted the properties of the resulting lignin, demonstrating the need for method-specific considerations to optimize lignin structural and functional characteristics for various applications.

2199

2200

2201

2202

2203

2204

2205

2206

2207

2208

2209

2210

2211

2212

2213

2214

2215

2216

2217

2218

2219

2220

2221

2222

2223

2224
<table><caption>2225 Table 6: Summary of some research studies on isolation of lignin from diverse lignocellulosic biomasses for diverse applications.</caption><thead><tr><td>Biomass used</td><td>Extraction methods involved</td><td>Properties of extracted lignin</td><td>Ref.</td></tr></thead><tbody><tr><td>Non-wood cellulosic biomass sources, including wheat straw, pine straw, alfalfa, kenaf, and flax fiber. Alfalfa yielded the most lignin (34%), followed by pine straw (22.65%), wheat straw (20.40%), and flax fiber (14.88%)</td><td><ul><li>Lignin was extracted from nonwood biomasses using a multi-step process.</li><li>Biomass was first pulped with an 85% organic acid mixture for 2 h.</li><li>Further delignification used PFA/PAA at 80°C for 2 h.</li><li>Delignified fibers were bleached, and lignin was precipitated and vacuum dried.</li></ul></td><td><ul><li>TGA revealed that lignin from wheat straw had the highest thermal stability with a char yield of 40.41%, followed by flax fiber (39.22%), alfalfa (35.04%), and pine straw (29.45%).</li><li>FTIR analysis revealed common features in lignin chemical structure, including formate ester and aromatic compounds.</li><li>DSC showed higher enthalpy measurements for lignin from flax fiber (190.57 J/g) and alfalfa (160.90 J/g), indicating better thermal stability.</li></ul></td><td>473</td></tr><tr><td>Typha capensis (TC), a highly acetylated grass</td><td><ul><li>Milling (MWL) : Lignin was extracted from TC using a modified Bjorkman method and analyzed.</li><li>Ionic Liquid (ILL) : TC was treated with [EMIm][OAc], and lignin was separated, purified, and analyzed.</li><li>Ethanol Organosolv (EOL) : TC underwent autohydrolysis, ethanol/water, and sulfuric acid treatment before lignin separation and analysis.</li></ul></td><td><ul><li>TC and MWL had high acetyl content, 11 wt% and 8 wt%, respectively.</li><li>ILL and EOL lost about 80% of their original acetyl groups.</li><li>NMR spectra showed MWL had the most acetyl content, while EOL had the least.</li><li>EOL experienced significant polysaccharide hydrolysis, and ILL may have acetylation shifts from lignin to cellulose.</li></ul></td><td>89</td></tr><tr><td>Eucalyptus urophylla</td><td><ul><li>Lignin was extracted using an ionic liquid-based microwave-assisted extraction (ILs-MAE) process, specifically utilizing [C2C1 im][OAc] and [C4C1 im]Cl ionic liquids, with varying microwave power and reaction times to assess extraction efficiency and lignin yield.</li></ul></td><td><ul><li>Up to 45.8% lignin was extracted using [C2C1 im][OAc] at 140 °C and 400 W.</li><li>Extracted lignin had molecular weights ranging from 730 to 3870 g/mol, showing varying depolymerization.</li><li>2D HSQC NMR analysis showed significant degradation of β-O-4' linkages and S/G ratio changes.</li><li>Thermal stability and sugar content varied, reflecting extraction parameter effectiveness.</li></ul></td><td>90</td></tr><tr><td>Empty fruit bunches (EFB), palm mesocarp fiber (PMF), and palm kernel shells (PKS) from oil palm biomass.</td><td><ul><li>Lignin was extracted with Pyridinium Formate (PyFor) under mild conditions.</li><li>Parameters such as particle size, temperature, and time were optimized.</li><li>The process was optimized using response surface methodology.</li><li>Regenerated lignin was filtered and dried.</li></ul></td><td><ul><li>Maximum lignin extraction efficiencies were 92.01% for EFB, 91.23% for PMF, and 90.70% for PKS.</li><li>The extraction process showed activation energies of 12 kJ/mol for EFB, 23 kJ/mol for PMF, and 28 kJ/mol for PKS.</li><li>The extracted lignins were characterized using FTIR and 'H NMR, and the sustainability of the PyFor solvent was confirmed.</li></ul></td><td>491</td></tr><tr><td>Sugarcane bagasse</td><td><ul><li>Alkaline extraction used 15% NaOH at 100°C for 90 minutes, producing alkaline lignin (AL).</li><li>Ethanosolv extraction applied ethanol-water mixtures at 200°C for 90 minutes, resulting in ethanosolv lignin (EL).</li><li>Hydrotropic extraction involved various solutions at 90°C for 6 hours, yielding hydrotropic extracted lignin (HEL).</li></ul></td><td><ul><li>Alkaline lignin (AL) had 57.85% carbon, a molecular weight of 2170 g/mol, and notable groups.</li><li>Ethanosolv lignin (EL) had 61.33% carbon, a higher molecular weight of 3640 g/mol, and the highest HHV.</li><li>Hydrotropic extracted lignin (HEL) also had 57.85% carbon, a molecular weight of 3802 g/mol, and similar HHV to AL.</li></ul></td><td>492</td></tr></tbody></table>
<table><tr><td>Etek lignin, a byproduct from the acidic processing of wood to produce fermentable sugars</td><td><ul><li>Lignin was precipitated by acidification or dilution with water in each extraction method.</li><li>Etek lignin underwent fast pyrolysis at 500°C in a fluidized bed reactor with short residence time.</li><li>Pyrolysis vapors were condensed, and aerosols were collected using electrostatic precipitators.</li><li>Pyrolysis oil was mixed with sand and extracted through Soxhlet extraction with hexane and methanol.</li><li>Resulting fractions were separated into soluble and insoluble types, then freeze-dried to obtain powders.</li></ul></td><td><ul><li>FTIR spectrum of HEL showed more aromatic and phenolic groups, with a maximum yield at 1.43 M sodium xylene sulfonate.</li><li>Pyrolytic lignins had varied carbon, hydrogen, and oxygen contents; heating values ranged from 22.7 to 27.2 MJ/kg.</li><li>Methanol-insoluble fraction had a lower heating value of 9.7 MJ/kg.</li><li>FTIR and 31P NMR analyses showed increased hydroxyl and carbonyl groups, with varied molecular weights.</li><li>Pyrolytic lignins had lower molecular weights than original Etek lignin; DI (dichloromethane insoluble) lignin fraction had the highest.</li><li>TGA revealed pyrolytic lignins decomposed at 110-120 °C; DI and WI (water immersed) fractions had greater stability.</li></ul></td><td>493</td></tr><tr><td>The efficacy of three different deep eutectic solvents (DES) was investigated for extracting lignin from four types of food processing residues: rice husks, sugarcane bagasse, coffee chaff, and corn stover</td><td><ul><li>Biomass was ground, sieved to ≤180 µm, and treated with DES in an oil bath.</li><li>The mixture was vacuum filtered, rinsed with ethanol, and precipitated with deionized water.</li><li>The precipitate was dried to obtain lignin.</li><li>Lignin was acetylated with acetic anhydride and pyridine for GPC analysis.</li></ul></td><td><ul><li>The extracted lignins showed varied molecular weight and polydispersity indices (PDI) based on the DES used.</li><li>DES acetic acid: choline chloride (AACC) produced lignins with reduced molecular weight and high PDI for rice husks and sugarcane bagasse, while lactic acid: choline chloride (LACC) was most effective for coffee chaff and formic acid: choline chloride (FACC) for corn stover.</li><li>Higher heating values (HHV) of the lignins extracted with AACC were notably higher than the control black liquor-derived lignin.</li></ul></td><td>480</td></tr><tr><td>Extracting lignin from bamboo biomass using nitrile-based ionic liquids (ILs) as pre-treatment solvents.</td><td><ul><li>The extraction process involved the use of synthesized nitrile-based ionic liquids, specifically 1-propyronitrile-3-butylimidazolium chloride ([C2CNBim]Cl), 1-propyronitrile-3-allylimidazolium chloride ([C2CNAim]Cl), 1-propyronitrile-3-(2-hydroxyethyl)imidazolium chloride ([C2CNHEim]Cl), and 1-propyronitrile-3-benzylimidazolium chloride ([C2CNBzim]Cl).</li><li>The bamboo biomass was treated with these ILs under controlled conditions (temperature, time, and particle size) to extract lignin.</li></ul></td><td><ul><li>The lignin was characterized by FTIR, NMR, TGA, and elemental analysis.</li><li>[C2CNBzim]Cl was the best IL, extracting up to 53% of lignin efficiently.</li><li>Cellulose crystallinity stayed the same, and lignin showed expected functional groups after extraction.</li><li>The ILs were highly recyclable, maintaining efficiency across several cycles.</li><li>Successful lignin isolation was confirmed through functional group analysis and extraction efficiency.</li></ul></td><td>489</td></tr><tr><td>Extraction of lignin from two types of biomass: softwood and brewer's spent grains (BSG)</td><td><ul><li>Lignin was extracted using deep eutectic solvents (DES) composed of choline chloride (ChCl) combined with two different hydrogen bond donors (HBDs): lactic acid (LA) and glycerol (Gly).</li><li>The pretreatment was conducted at temperatures of 60°C and 80°C. The process involved mixing the biomass with DES, followed by filtration, ethanol washing, and precipitation of lignin using ethanol/water mixture as an antisolvent. The resulting lignin precipitate was then dried.</li></ul></td><td><ul><li>Lignin features varied based on the DES and temperature used in extraction.</li><li>ChCl yielded higher β-O-4 linkages and narrow molecular weight distributions, especially at 80°C.</li><li>ChCl resulted in lower yields and less β-O-4 preservation compared to other methods.</li><li>NMR showed ChCl preserved G subunits and β-O-4 bonds better in softwood lignin.</li></ul></td><td>494</td></tr></table>
<table><tr><td>Three types of poplar species were utilized: wild-type poplar (P. nigra x P. maximowiczii), and two genetically modified variants with high-S (F5H-64) and low-S (1035-41) lignin content.</td><td><ul><li>Lignin was extracted using acetic acid/formic acid/water, acetone/water, and methanol/water as solvent mixtures.</li><li>Biomass was heated with solvents, then filtered, concentrated, and precipitated to isolate lignin.</li><li>Methanol treatment yielded 58%-69% lignin, higher than 47%-54% from acetic acid/formic acid.</li><li>Acetone extraction resulted in 62%-67% lignin yield, less effective than methanol.</li></ul></td><td><ul><li>Lignin properties varied based on the solvent used for extraction.</li><li>Methanol yielded more monomeric phenolic products, achieving over 60% product yield.</li><li>Methanol preserved lignin's structure by minimizing carbon-carbon bond formation.</li><li>SEM and NMR analyses showed methanol produced larger, regular particles with unique substitution patterns.</li></ul></td><td>495</td></tr><tr><td>Wheat straw and rice husk as lignocellulosic biomass sources</td><td><ul><li>Lignin was extracted using protic ionic liquids consisting of pyridinium cations and dihydrogen phosphate anions (H<sub>2</sub>PO<sub>4</sub><sup>-</sup>).</li><li>The ILs were synthesized by treating pyridine with varying moles of 85% phosphoric acid (H<sub>3</sub>PO<sub>4</sub>).</li><li>Biomass samples were pretreated in these ionic liquids at temperatures ranging from 70°C to 100°C for 30 to 120 minutes.</li><li>Post-treatment, lignin was separated using acetone-water anti-solvent mixture, filtered, and then purified by centrifugation and freeze-drying.</li></ul></td><td><ul><li>The extracted lignin yields were optimal at 73% for wheat straw and 72% for rice husk under the best conditions (100°C for 2 hours).</li><li>The lignin showed reduced intensity in FT-IR peaks related to aromatic rings and phenolic OH groups, indicating successful delignification.</li><li>HSQC NMR analysis revealed that the lignin structure retained guaiacyl and syringyl fragments, with some condensation observed, reflecting the effectiveness and mildness of the extraction process.</li></ul></td><td>91</td></tr><tr><td>Various types of biomass, including wheat straw, eucalyptus, and pine</td><td><ul><li>The extraction employed a combination of 1,4-butanediol (BDO) and p-toluenesulfonic acid (pTsOH) in an aqueous solution.</li><li>Molecular dynamics simulations revealed how lignin dissolved at the molecular level.</li><li>The conditions included a 70% BDO aqueous solution mixed with 10% pTsOH at temperatures ranging from 90°C to 150°C.</li><li>This approach was optimized to maintain lignin native structure while avoiding excessive condensation.</li></ul></td><td><ul><li>The extracted lignin retained high levels of β-O-4 linkages, with preservation rates reaching up to 95%.</li><li>The lignin showed high yields (over 80% from eucalyptus and around 50% from resistant conifer wood) and was found to have a low condensation level, making it suitable for high-value applications.</li><li>The extracted lignin also demonstrated potential as an effective ingredient in chemical sunscreens, significantly enhancing the sun protection factor (SPF) compared to untreated samples.</li></ul></td><td>496</td></tr><tr><td>Kenaf fiber biomass sourced from Chuping plantation site in Malaysia</td><td><ul><li>The lignin extraction involved a two-step process.</li><li>kenaf fibers were pretreated with a natural deep eutectic solvent (NADES) consisting of lactic acid and choline chloride at molar ratios of 1:12 and 1:15.</li><li>Fibers were then subjected to acid hydrolysis using 72% sulfuric acid to remove carbohydrates, then the lignin was extracted, filtered, and dried.</li></ul></td><td><ul><li>The lignin extracted using NADES showed a slight increase in carbon and nitrogen percentages compared to commercial lignin.</li><li>NADES-extracted lignin exhibited a smoother and wavier surface compared to the irregular texture of commercial lignin.</li><li>FTIR spectra indicated similar functional groups but with slight variations in intensity and position.</li><li>XRD analysis revealed a slight decrease in crystallinity after NADES pretreatment.</li><li>TGA and DSC analysis showed that NADES-extracted lignin had a different thermal degradation profile compared to commercial lignin, with varying decomposition temperatures and enthalpy values.</li></ul></td><td>490</td></tr></table>
<table><tr><td>Residual lignocellulosic biomass from Ocote pine (Pinus montezumae Lamb.) including sawdust and bark sourced from the forest fields of Rancho Peñitas and Guzmán in San Joaquín, Michoacán, Mexico</td><td><ul><li>The Kraft process was utilized for delignification, employing sodium hydroxide (NaOH) and sodium sulfide (Na<sub>2</sub>S) in a 600 mL Parr reactor.</li><li>The biomass (50 g of sawdust or bark) was digested in a white liquor solution at 170°C for 50 minutes under pressure (8 bar).</li><li>Post-digestion, lignin was recovered through filtration and acidification, then purified by repeated washing with deionized water and dried at 50°C.</li></ul></td><td><ul><li>The extracted lignin exhibited characteristic bands for aromatic compounds and phenolic groups, with more intense signals for sawdust lignin.</li><li>Lignin from both sawdust and bark demonstrated high thermal stability with sawdust lignin showing complete decomposition above 800°C, whereas bark lignin retained stability due to its higher aromatic content.</li><li>Sawdust lignin had a higher calorific value (28.75 MJ/kg) compared to bark lignin (23.61 MJ/kg), indicating better energy content. Both types showed low ash content and minimal sulfur, making them suitable for biofuel production.</li></ul></td><td>488</td></tr></table>

2226 BDO refers to 1,4-butanediol, while pTsOH stands for p-toluenesulfonic acid. TGA is thermogravimetric analysis, and FTIR represents Fourier-transform infrared spectroscopy. DSC is differential scanning calorimetry. PFA/PAA refers to peracetic and phosphoric acids. MWL is milled wood lignin, ILL is ionic liquid lignin, and EOL is ethanol organosolv lignin. PyFor stands for pyridinium formate, AL is alkaline lignin, and EL is ethanosolv lignin. HEL is hydrotropic extracted lignin, DI is dichloromethane insoluble lignin, and WI is water immersed lignin. DES refers to deep eutectic solvents, ChCl is choline chloride, and HBDs are hydrogen bond donors. NADES are natural deep eutectic solvents, NaOH is sodium hydroxide, and Na<sub>2</sub>S is sodium sulfide.
2231

## 2.6.2. Lignin properties

2232

2233

2234

2235

2236

2237

2238

2239

2240

2241

2242

2243

2244

2245

2246

2247

2248

2249

2250

2251

Lignin, an irregular and heterogeneous polymer, plays a crucial role in modulating liquid transport within plants, allowing them to grow tall and compete for sunlight. Unlike cellulose, which forms crystalline structures, lignin amorphous nature results in an irregular, three-dimensional polymer network. This structure contributes to its flexibility and ability to fill spaces within the cell wall matrix, enhancing the mechanical strength of plant tissues. The composition of lignin varies depending on its source²¹³. For instance, in softwoods like pine and spruce, lignin primarily consists of coniferyl alcohol units with some p-coumaryl units and minimal concentrations of sinapyl alcohol units. In contrast, hardwoods such as beech, birch, and oak contain higher concentrations of sinapyl alcohol units in their lignin³¹⁸. Native lignin is insoluble in water, and during the cooking process, its solubilization is essential to separate it from the fiber fraction⁵⁶. Lignin comprises polar groups (such as hydroxyl) and nonpolar hydrocarbon and benzene rings (including aromatic sites, alcohols, methoxyl, carboxyl, and carbonyl functionalities), enabling it to react with various organic chemicals to produce synthetic polymers like resins, polyurethanes, and polyesters for industrial applications⁴⁹⁷. These functionalities facilitate chemical reactions such as esterification, alkylation, etherification, hydroxypropylation with epoxides, and urethanization via isocyanate or non-isocyanate routes⁴⁹⁸. Figure 29 illustrates chemical transformations diversifying chemical functionalities on lignin. Lignin possesses high strength, resistance, and rigidity against ultraviolet light, making it suitable for heat and sound insulation⁴⁹⁹. Its molecular weight and chemical composition depend not only on plant species but also on the plant part, resulting in various compositions within the same plant. For instance, lignin carbohydrate complexes extracted from hardwood and softwood have molecular weight ranges of 9800 - 17600 and 10000 - 13000 g/mol, respectively⁵⁰⁰,⁵⁰¹.

2252

2253

2254

2255

2256

2257

2258

2259

2260

2261

2262

2263

2264

2265

2266

The aromatic nature of lignin endows it with unique physicochemical properties, including UV-absorbing capabilities, which protect plants from harmful solar radiation. Additionally, lignin is highly resistant to biodegradation, contributing to the longevity of plant-derived materials in natural environments ⁵⁰²,⁵⁰³. This resistance poses challenges in lignin valorization and recycling efforts, as traditional chemical and biological processes for lignin degradation are often inefficient and costly. Moreover, the thermal stability of lignin is influenced by various factors, including interunit structures, functional groups, degree of condensation, and molecular weights ¹⁵⁴. Lignin exhibits moderate stability at elevated temperatures, with decomposition typically occurring within the temperature range of 200 to 600°C, peaking around 400°C. This decomposition involves the elimination of formic acid, formaldehyde, carbon dioxide, and water from the degradation of phenylpropane side chains at elevated temperatures ⁵⁰⁴. At temperatures between 500 and 700°C, degradation of the lignin backbone intensifies, leading to the release of volatile products such as carbon monoxide, carbon dioxide, and hydrogen ⁵⁰⁵. Lignin is also recognized for its potential as a renewable source of carbon in carbon fiber production due to its high carbon content and thermal stability. By pyrolyzing lignin at high temperatures, it can be converted into carbon fibers suitable for aerospace, automotive, and other high-performance applications ⁴⁹³,⁵⁰⁶.

2267

2268

2269

2270

2271

2272

2273

Lignin and lignin-based materials possess both antioxidant and antimicrobial properties ⁵⁰⁷. Studies have shown that syringic acid, a lignin-derived compound, can modulate MMP expression and control MMP-1 production via the AP-1 mechanism, increasing the survival rate of UVB-damaged HaCaT cells, indicating potential applications in cosmetics ⁵⁰⁸. Additionally, nanoparticles derived from a silver-infused lignin core have demonstrated antimicrobial properties, effectively neutralizing common pathogens, highlighting the potential of lignin-based materials as antimicrobial agents ⁵⁰⁹. Moreover, due to its exceptional mechanical properties, lignin has been explored as a reinforcement material to improve the
2274

2275

2276

2277

2278

2279

2280

mechanical properties of resulting polymers. Özparpacu et al. 510 found a significant influence of lignin on the axial elastic modulus of poplar wood, attributing this enhancement to lignin aromatic and heterocyclic structure, which improved the mechanical properties of wood biomass. In addition, Cousins 511 conducted experiments to measure the elastic modulus of two types of lignins (periodate and Klason lignins) at various moisture contents. They found that the Young's modulus of periodate lignin ranged from 3.1x10⁹ to 6.7x10⁹ Pa, and the shear modulus ranged from 1.2x10⁹ to 2.1x10⁹ Pa as moisture content decreased. Similarly, Klason lignin exhibited similar behavior, although its moduli were consistently lower 511.

2281

2282

2283

2284

2285

2286

2287

2288

2289

From a mechanical perspective, lignin contributes significantly to the structural integrity of plant tissues, providing rigidity and strength. Its role in plant cell walls is crucial for maintaining the overall architecture and supporting the plant upright growth 512. Lignin mechanical properties, such as its Young's modulus, tensile strength, and toughness, vary depending on factors like its molecular weight, chemical composition, and degree of polymerization. These properties can be tailored through various processing methods, such as chemical modification, blending with other polymers, or altering its molecular structure during extraction processes 153,200,513. Lignin-based composites were developed by incorporating lignin into matrices like polymers and bioplastics, resulting in materials with enhanced mechanical properties and reduced environmental impact compared to traditional petroleum-based counterparts 514,515.

<figure><img src="image_54.png" /><figcaption>**Figure 29:** Summary of chemical transformations to diversify chemical functionalities on lignin. Reproduced with permission from Ref. 498 Copyright © 2019 MDPI.</figcaption></figure>

2290

2291

2292

2293

### 2.6.3. Lignin (bio)sensing applications

2294

2295

2296

2297

2298

Recent research has increasingly turned to lignin-based composites for advanced (bio)sensing applications, reflecting a growing interest in utilizing this abundant and renewable biopolymer 516-518. Lignin, a complex aromatic polymer found in plant cell walls, offers unique properties that enhance the performance of sensing materials. Recent studies have demonstrated the development of lignin-based composites that exhibit exceptional sensitivity, selectivity, and stability for various sensing applications
2299 517-520. For instance, lignin has been incorporated into nanostructured materials and hydrogels, resulting in highly effective sensors for detecting environmental pollutants, biological molecules, and hazardous substances 518,521. These composites often leverage the inherent chemical versatility of lignin, enabling functionalization with additional sensing moieties or conductive materials to improve detection limits and response times. Noteworthy advancements include lignin-based electrochemical sensors with enhanced electroactive properties, making them suitable for detecting trace levels of analytes 519, and lignin-derived photonic sensors that utilize the polymer unique optical properties for highly sensitive biosensing applications 522,523. The use of lignin not only contributes to the development of more sustainable and eco-friendly sensing technologies but also addresses critical challenges such as cost and material availability 516,519,523. Recent research works involving the utilization of lignin-based composites for (bio)sensing applications are highlighted in the Table 7.

2310 The various studies reviewed in the Table 7 reveal significant advancements in sensor technologies leveraging lignin-based materials, each contributing unique insights into material performance and application. Gold electrodes modified with lignin nanoparticles (LNPs) revealed that kraft lignin nanoparticles (KLNPs) notably hindered electron transfer compared to organosolv lignin nanoparticles (OLNPs), indicating that different lignin modifications could drastically affect sensor performance and sensitivity in glucose detection 520. Meanwhile, lignin-scribed graphene (LSG) combined with nitrogen-doped graphene quantum dots (N-GQDs) and silver nanoparticles (Ag NPs) demonstrated exceptional sensitivity (1 fM) for detecting Troponin I, underscoring the effectiveness of hybrid nanocomposites in medical diagnostics 519. In another study, nitrogen-doped laser-scribed graphene (N-LSG) modified with a Ti3C2Tx/Prussian blue (PB) composite achieved enhanced electrochemical activity for multiple analytes, emphasizing the significant improvement in sensor performance through advanced material engineering 524. Carbon-based conductive inks from lignin and their application in detecting uric acid and catechol illustrated the potential of lignin-derived materials in producing cost-effective and efficient biosensors for electroanalytical applications 516. The development of carbon foams incorporating graphene oxide (GO) and reduced graphene oxide (rGO) showed improved electrochemical properties and performance for ammonia detection, highlighting the importance of optimizing additive concentrations and processing methods 517. In the realm of wearable sensors, electrospun carbon fibers derived from Eucalyptus globulus lignin exhibited distinct responses to various human motions, suggesting potential for customized sensor applications 525. Similarly, lignin-based polyurethane copolymers doped with multiwall carbon nanotubes (MWCNTs) achieved high conductivity with a low percolation threshold, demonstrating their utility in potentiometric chemical sensors 526. Furthermore, lignin-derived graphene composites integrated with MoS2 and silver nanoparticles (Ag NPs) achieved remarkable sensitivity for Troponin I with a detection limit of 100 attomolar, showcasing superior performance in biomarker detection 527. In addition, the lignin/polypyrrole composite films demonstrated high specific capacitance and surface area, indicating their potential for advanced supercapacitor applications 528. Carbonized lignin screen-printed electrodes with immobilized algae cells achieved high sensitivity for atrazine detection, presenting a sustainable approach for agricultural monitoring 518. Lastly, lignin-based phenolic-resin-derived carbon catalysts, incorporating CoNi/biochar, achieved a low detection limit for 2-nitrophenol, emphasizing the effectiveness of combining lignin-derived carbon materials with metal catalysts for sensitive electrochemical applications 529. In summary, these research studies reflect the versatility of lignin-based materials in enhancing the performance of sensors and energy storage devices, while also highlighting the need for further optimization to address specific analytical and practical challenges.
<table><caption>2342 Table 7: Overview of research studies utilizing lignin-based materials for (bio)sensing applications and energy storage devices.</caption><thead><tr><td>Electrode materials</td><td>Analytes/measured parameters</td><td>Detection limit</td><td>Major findings</td><td>Ref.</td></tr></thead><tbody><tr><td>Gold electrodes modified with lignin nanoparticles (LNPs), specifically organosolv (OLNPs) and kraft lignin (KLNPs)</td><td>Glucose</td><td>--------</td><td><ul><li>The study demonstrated that LNP-modified gold electrodes, using OLNPs and KLNPs, significantly impacted electrochemical behavior, with KLNPs showing a stronger inhibition of electron transfer.</li><li>The electrochemical analysis revealed decreased faradaic current and increased ΔE<sub>pl</sub> in cyclic voltammetry, and larger semicircles in Nyquist plots, indicating reduced electron transfer kinetics.</li><li>Biosensors assembled with concanavalin A (ConA) and glucose oxidase (GOx) exhibited glucose detection sensitivities of (4.53 ± 0.467) µA mM<sup>-1</sup> cm<sup>2</sup> for OLNPs and (13.74 ± 1.84) µA mM<sup>-1</sup> cm<sup>2</sup> for KLNPs.</li></ul></td><td>520</td></tr><tr><td>Lignin-scribed graphene (LSG) conjugated with nitrogen-doped graphene quantum dots (N-GQDs) and lignin-derived silver nanoparticles (Ag NPs)</td><td>Troponin I, a cardiac biomarker for Acute Myocardial Infarction</td><td>1 fM (30 fg/mL)</td><td><ul><li>The developed nanocomposite exhibited an optimal conduction mechanism with uniformly distributed Ag NPs and N-GQDs on the LSG surface.</li><li>It demonstrated high selectivity and sensitivity for Troponin I detection, with the sensor showing excellent linearity, repeatability, and stability.</li><li>The impedance spectroscopy results indicated a very low detection limit of 1 fM, making this nanocomposite a promising tool for precise and sensitive medical diagnostics.</li></ul></td><td>519</td></tr><tr><td>Nitrogen-doped laser-scribed graphene (N-LSG) derived from lignin-based precursors, modified with a Ti3C2Tx/Prussian blue (PB) composite</td><td>Glucose, lactate, alcohol</td><td></td><td><ul><li>The N-LSG electrodes, produced using a CO<sub>2</sub> laser scribing process, were binder-free, hierarchical, and exhibited enhanced electrochemical activity due to high conductivity (2.8 Ω/sq) and rich active edge-plane sites.</li><li>The addition of Ti3C2Tx/PB composite and enzyme functionalization significantly improved the electrochemical performance of the electrodes for detecting glucose, lactate, and alcohol, achieving comparable results to existing on-chip carbon-based biosensors.</li></ul></td><td>524</td></tr><tr><td>Three-dimensional N, S co-doped lignin-based carbon microsphere/graphene composite hydrogel (GH-NSCMS)</td><td>Supercapacitor performance metrics; tetracycline for molecularly imprinted electrochemical sensors (MIECS).</td><td>Tetracycline: 5 × 10<sup>-8</sup> mol L<sup>-1</sup></td><td><ul><li>The GH-NSCMS electrode exhibits a specific capacitance of 434.6 F/g at 0.5 A/g and retains 94.15% capacitance after 5,000 cycles, demonstrating excellent stability for supercapacitor applications.</li><li>For tetracycline detection, the MIP electrochemical sensor using GH-NSCMS shows high sensitivity with a wide linear range of 0.1–50 µM and a low detection limit of 5 × 10<sup>-8</sup> mol L<sup>-1</sup>, benefiting from the high conductivity and imprinting accuracy of the composite.</li></ul></td><td>521</td></tr><tr><td>Carbon-based conductive inks derived from carbonized lignin (Eucalyptus globulus waste) combined with cyclohexanone and cellulose acetate</td><td>Uric acid and catechol</td><td>0.3 µM for uric acid; 2.01 µM for catechol</td><td><ul><li>A stable conductive ink was developed with optimal conductivity and rheological properties, featuring an electrochemically active area of 0.1813 cm<sup>2</sup>, surpassing that of petroleum-based inks (0.1420 cm<sup>2</sup>).</li><li>The ink was used to produce screen-printed electrodes that demonstrated effective performance in detecting uric acid and catechol, while also showcasing biocompatibility with laccase enzyme.</li></ul></td><td>516</td></tr></tbody></table>
<table><tr><td>Carbon foams (CFs) produced from lignin-phenol-formaldehyde (LPF) resin with 1%, 2%, and 4% graphene oxide (GO) and reduced graphene oxide (rGO) additives</td><td>Ammonia</td><td></td><td><ul><li>The integration of GO and rGO into LPF resin-based carbon foams resulted in significant enhancements in electrochemical properties.</li><li>Carbon foams with 2% GO (GO2%) exhibited a 39% and 62% larger electroactive area compared to control and 2% rGO sensors, respectively.</li><li>The study demonstrated that the thermal decomposition and reduction processes effectively removed oxygen groups from GO, improving the electron transfer and overall electrochemical performance of the sensors.</li></ul></td><td>517</td></tr><tr><td>Electrospun ultrathin carbon fibers derived from Eucalyptus globulus lignin (EKL) and sugarcane bagasse Kraft lignin (BKL)</td><td>Human body motions (finger bending, arm bending, finger pressing)</td><td>--------</td><td><ul><li>Carbon fiber-based sensors was developed from EKL and BKL lignins and investigated their chemical structures.</li><li>EKL, with a slightly linear structure featuring sinapyl and coniferyl alcohols, produced sensors with high signal amplitude (ΔR/R₀ ≈ 9 × 10⁴) for finger bending motions.</li><li>In contrast, BKL, which formed more amorphous carbon and graphite, showed a larger variation in resistance for arm bending (ΔR/R₀ ~380) and smaller changes for finger pressing (ΔR/R₀ < 10).</li></ul></td><td>525</td></tr><tr><td>Modified eucalyptus kraft lignin doped with multiwall carbon nanotubes (MWCNTs) incorporated into a crosslinked elastomeric polyurethane copolymer</td><td>Potentiometric chemical sensors</td><td>--------</td><td><ul><li>A conductive lignin-based polyurethane copolymer with MWCNTs was fabricated, demonstrating significantly enhanced electrical conductivity while maintaining thermal and viscoelastic properties.</li><li>The addition of MWCNTs resulted in a very low percolation threshold of 0.18% (w/w), attributed to the oriented distribution of MWCNTs within lignin clusters.</li><li>The polymer showed improved conductivity without compromising stability or performance, making it suitable for use in potentiometric chemical sensors.</li><li>The copolymer low glass transition temperature of approximately -49 °C and its stability in various solvents enhanced its suitability for self-plasticizing sensor applications.</li></ul></td><td>526</td></tr><tr><td>Lignin-derived graphene (3D LSG) integrated with MoS₂ and silver nanoparticles (Ag NPs)</td><td>Troponin I (a biomarker for Acute Myocardial Infarction)</td><td>100 attomolar</td><td><ul><li>A lignin-derived graphene-based biosensor was fabricated with enhanced performance by incorporating MoS₂ and Ag NPs.</li><li>The hybrid material, 3D LSG_MoS₂_Ag NPs-2.0, exhibited improved surface area and sensitivity due to the addition of MoS₂ nanoflowers and Ag NPs.</li><li>This biosensor demonstrated high analytical performance with a detection limit of 100 attomolar for Troponin I, a sensitivity of 31.45 µA mM⁻¹ cm⁻², and excellent stability (87%) and reproducibility (relative standard deviation of 3.8%).</li><li>The biosensor achieved approximately a 4-fold increase in selectivity and high specificity, making it a promising tool for detecting Troponin I in clinical diagnostics.</li></ul></td><td>527</td></tr><tr><td>Lignin/polypyrrole (PPy) composite electrode films</td><td>Electrochemical performance metrics in a 1 M H₂SO₄ electrolyte</td><td></td><td><ul><li>The lignin/PPy composite films, designed with microporous and mesoporous structures through electrostatic spinning, carbonization, and in situ polymerization, demonstrated enhanced electrochemical performance.</li><li>The incorporation of PPy into lignin carbon nanofibers resulted in a specific capacitance of 213.7 F/g at a current density of 1 A/g, surpassing other carbon-based materials tested.</li></ul></td><td>528</td></tr></table>
<table><tr><td>Polyurethane-lignin copolymer blended with multi-walled carbon nanotubes (MWCNTs), using LignoBoost® kraft lignin</td><td>Copper ions (Cu<sup>2+</sup>)</td><td><ul><li>The specific surface area of the composite reached 872.60 m<sup>2</sup>/g, with a reduced average pore size of 2.50 nm, highlighting the formation of a compact 3D conductive network.</li></ul></td><td>530</td></tr><tr><td>Carbonized lignin screen-printed electrodes with immobilized whole cells of Chlamydomonas reinhardtii UV180 mutant</td><td>Nanoformulated atrazine encapsulated in zein and chitosan-doped poly-ε-caprolactone (PCL-Ch) nanoparticles</td><td>0.9 nM for atrazine-zein and 1.1 nM for atrazine-PCL-Ch</td><td><ul><li>A polyurethane-lignin copolymer doped with MWCNTs successfully synthesized, specifically using LignoBoost® kraft lignin, which contained increased polyphenolic groups from tannins.</li><li>This copolymer demonstrated enhanced electrical conductivity and was utilized in all-solid-state potentiometric sensors.</li><li>The sensors showed high selectivity and sensitivity towards Cu<sup>2+</sup> ions and exhibited long-term stability.</li><li>Electrical impedance and conductivity measurements confirmed that the interaction between MWCNTs and lignin significantly improved the polymer electrical properties, with a notable percolation threshold of 0.77% MWCNTs in the lignin-based polymer.</li><li>Compared to technical lignins, LignoBoost® kraft lignin higher polyphenolic content contributed to superior ion-exchange properties and enhanced sensing performance.</li></ul></td><td>518</td></tr><tr><td>Lignin-based phenolic-resin-derived carbon with CoNi/biochar catalyst (synthesized via in situ pyrolysis)</td><td>2-nitrophenol</td><td>0.0132 μM</td><td><ul><li>The biosensor demonstrated a highly sensitive and eco-friendly approach for detecting nanoformulated atrazine with linear dose-response curves in the 0.1 to 5 μM range.</li><li>It showed no interference from various contaminants and wastewater matrix effects, with recovery rates of 106 ± 8% for atrazine-zein and 93 ± 7% for atrazine-PCL-Ch.</li><li>The sensor exhibited a working stability of 10 hours, proving effective for sustainable agricultural monitoring</li></ul></td><td>529</td></tr></table>
2344

2345

2346

2347

2348

Lignin-based materials are emerging as promising candidates for a wide range of applications, including sensing and biosensing. The inherent aromatic structure of lignin imparts a rigid character to polymeric systems, ensuring excellent thermal and mechanical properties in resulting materials. Moreover, the phenolic and aliphatic hydroxyl groups present in lignin serve as chemical functionalities suitable for various applications<sup>200,531</sup>.

2349

**Chemical and environmental sensors.** Faria et al.⁵²⁶ modified eucalyptus kraft lignin-based polyurethane by incorporating multiwall carbon nanotubes (MWCNTs) to produce a conductive copolymer for use in ion-selective membranes for potentiometric chemical sensor applications. This hybrid material demonstrated high stability in aqueous solutions, with a reproducibility potential of 2% in a 0.1 mmol/L chromate solution over a three-month measurement period⁵²⁶. Similarly, Chokkareddy and coworkers⁵³² developed an innovative nanocomposite consisting of multiwalled carbon nanotubes, copper oxide nanoparticles, and lignin polymer, serving as a glassy carbon electrode modifier for the sensitive detection of chlorogenic acid in both artificial and coffee samples via differential pulse voltammetry⁵³². Under optimized conditions, the nanocomposite-modified electrode exhibited high sensitivity with low detection limits. When applied to real coffee samples, the hybrid electrode showed a recovery rate ranging from 97% to 106%⁵³². Stergiou et al.⁵³³ introduced lignin-modified glassy carbon electrodes as transducers for ozone detection, as demonstrated through impedimetric and cyclic voltammetric studies. The findings supported the feasibility of employing a polymer degradation-based impedimetric sensor for ozone monitoring, suggesting potential applications in industrial and technical settings⁵³³. Wang et al.⁵²⁵ devised carbon fibers derived from *Eucalyptus globulus* lignin and sugarcane bagasse kraft lignin capable of detecting specific human body motions. These lignin-based piezoresistive sensors showed promise for wearable electronics applications⁵²⁵.

2350

2351

2352

2353

2354

2355

2356

2357

2358

2359

2360

2361

2362

2363

2364

2365

**Bioimaging and biomedical applications.** Xu et al.⁵³⁴ developed lignin-sulfonate/graphene quantum dots core/shell hybrids for label-free, sensitive, and selective detection of Fe³⁺. The resulting sensor exhibited outstanding sensitivity and selectivity towards Fe³⁺ in both artificial and lake water samples, with a detection limit as low as 0.5 nM⁵³⁴. Rai et al.⁵³⁵ synthesized water-soluble reduced fluorescent carbon dots using lignosulfonate lignin as a carbon source for curcumin nano-carrier and bioimaging applications, suggesting potential for cancer diagnosis and treatment⁵³⁵. Pillai et al.⁵³⁶ conducted green synthesis of lignin-based fluorescent nanocolorants for live cell imaging, demonstrating non-toxic and efficient materials with high fluorescent intensity for live cell fluorescent imaging, particularly with L929 cells⁵³⁶.

2366

2367

2368

2369

2370

2371

2372

2373

**Biochemical sensing.** Lei et al.⁵²⁴ developed laser-scribed graphene electrodes derived from lignin for biochemical sensing, which exhibited remarkable electrochemical activity and were decorated with MXene/Prussian Blue and functionalized with catalytic enzymes for detecting glucose, lactate, and alcohol⁵²⁴. Additionally, Jędrzak et al.⁵³⁷ also immobilized glucose oxidase on silica-lignin system-based carbon paste electrodes to develop an enzymatic biosensor for studying glucose oxidation electrochemically. The biosensor displayed high sensitivity and selectivity, with a linear response range and a low detection limit for glucose. It was also utilized for immunosensing applications, detecting HIV p17 peptide with high sensitivity and selectivity⁵³⁷.

2374

2375

2376

2377

2378

2379

2380

2381

**Stress and strain sensing.** Nguyen et al.⁵³⁸ synthesized lignin-based renewable shape-memory materials for switchable electrical conductivity in stress/strain-sensing applications, achieving excellent results in devices for detecting human motion and monitoring stress history⁵³⁸. Moreover, Xue et al.⁵³⁹ developed a nanocomposite material based on silver nanoparticles and biorefinery wood lignin for optical sensing

2382

2383

2384

2385
applications. The sensor exhibited potential as a colorimetric sensor and plasmonic resonance energy acceptor for detecting $Hg^{2+}$ and rhodamine B, respectively $^{539}$.

**Humidity sensing.** Chen and coworkers $^{540}$ exploited lignosulfonate derived from biomass and graphene oxide to develop an environmental humidity sensor, which exhibited a maximum response of 298% for 97% relative humidity with a 3 wt% thin film. The escalating demand for disposable electrode-based portable devices in point-of-care testing necessitates low-cost and sustainable mass production of electrodes $^{540}$. In a recent study conducted by Gigli et al. $^{541}$, composite nanoparticles (Figure 30A) comprised of lignin (LN) and chitosan (CS), synthesized via layer-by-layer (LBL) and nanoprecipitation (NP) methods, were investigated using CV (Figure 30B-C) and electrochemical impedance spectroscopy (EIS) (Figure 30D) for electrochemical responsiveness. Electrochemical reversibility depended on preparation method, chitosan molecular weight (MW), and lignin type $^{541}$. Nanoprecipitation with Kraft lignin (KL) produced the most responsive nanodevice, indicating effective interactions between biopolymers $^{541}$. Chitosan steric hindrance affected reversibility, with low-medium MW chitosan yielding the best results. Field emission scanning electron microscopy and X-ray analyses revealed chitosan distribution within nanoparticles, influencing aggregate formation. Chitosan effect varied with lignin type, being positive with KL and detrimental with enzymatic hydrolysis lignin (EHL), likely due to different interaction networks. LNPs/CS, prepared easily and sustainably, showed superior electrochemical efficiency, suggesting a promising eco-friendly platform design $^{541}$.

<figure><img src="image_55.png" /><figcaption>**Figure 30:** (A) Schematic representation of the synthesis of LNPs/CS using two methods: Pathway A illustrates the nanoprecipitation method, while Pathway B depicts the layer-by-layer (LbL) assembly method. (B) Cyclic voltammograms (CVs) of various KLNP platforms: KLNPs/GCE (black), KLNPs/CS1/GCE (red), KLNPs/CS2/GCE (blue), and KLNPs/CS3/GCE (green). Redox probe: 5 mM [Fe(CN)₆]³⁻/⁴⁻ in 0.1 M KCl solution, scan rate: 50 mV s⁻¹. (C) (a) CVs of OLNP platforms synthesized by the nanoprecipitation method: OLNPs/GCE (black), OLNPs/CS1/GCE (red), OLNPs/CS2/GCE (blue), and OLNPs/CS3/GCE (green). (b) CVs of EHLNP platforms synthesized by the nanoprecipitation method: EHLNPs/GCE (black), EHLNPs/CS1/GCE (red), EHLNPs/CS2/GCE (blue), and EHLNPs/CS3/GCE (green). Redox probe: 5 mM [Fe(CN)₆]³⁻/⁴⁻ in 0.1 M KCl solution, scan rate: 50 mV s⁻¹. (D) Nyquist plots comparing Np-KLNPs/CS2/GCE (red) and Np-OLNPs/CS3/GCE (blue), measured in 5 mM [Fe(CN)₆]³⁻/⁴⁻ in 0.1 M KCl solution. The inset shows the equivalent circuit used for fitting the experimental data. Reproduced with permission from Ref. $^{541}$, Copyright © 2022 American Chemical Society.</figcaption></figure>
**Lactate biosensors.** Meng et al.⁵⁴² presented a green approach utilizing biomass lignin conversion, laser lithography, water lift-off, and NaBH₄ treatment was presented to create graphene electrodes for electrochemical lactate biosensors (Figure 31A). Laser lithography efficiently converted lignin into porous laser-induced graphene (LIG), optimized for conductivity and substrate attachment⁵⁴². Water-based patterning facilitated the formation of porous LIG (P-LIG), further reduced to P-rLIG with NaBH₄. LIG, P-LIG, and P-rLIG electrodes were crafted into freestanding working electrodes. CV and EIS analysis revealed varied peak currents and separations. P-LIG showed enhanced kinetics due to removed insulating salts and exposed pores⁵⁴². P-rLIG exhibited the highest current density and lowest separation, indicating improved conductivity and electron transfer rates, ideal for biosensors (Figure 31B). The resulting electrodes exhibited enhanced electrochemical kinetics, enabling the fabrication of disposable lactate biosensors with excellent analytical performance, promising for sustainable biosensor manufacturing (Figure 31C)⁵⁴².

<figure><img src="image_56.png" /><figcaption>**Figure 31:** (A) A sustainable approach converting lignin into graphene-based disposable electrodes for electrochemical biosensors. (B) Electrochemical kinetics evaluation: (a) cyclic voltammograms of LIG, P-LIG, and P-rLIG electrodes in [Fe(CN)₆]³⁻/⁻; (b) EIS of LIG, P-LIG, and P-rLIG electrodes in [Fe(CN)₆]³⁻/⁻. (C) Performance of electrochemical lactate biosensors: (a) cyclic voltammograms of PB/P-rLIG electrode in H₂O₂; (b) amperometric response to H₂O₂; (c) calibration curve for H₂O₂; (d) amperometric response to lactate; (e) calibration curve for lactate; (f) interference study; (g) shelf-life study; (h) correlation with standard assay for real sweat sample analysis. Reproduced with permission from Ref. ⁵⁴², Copyright © 2022 Elsevier.</figcaption></figure>

**Flexible Supercapacitors.** The scientific community has recently explored the use of lignin in the development of flexible supercapacitors with high power density. Park et al.⁵⁴³ fabricated flexible supercapacitors by integrating chemically cross-linked lignin hydrogel electrolytes with electrospun
2440 lignin/polyacrylonitrile nanofiber electrodes. These devices exhibited a high capacitance of 129.23 F g⁻¹ and delivered a maximum energy and power density of 4.49 Wh kg⁻¹ and 2.63 kW kg⁻¹, respectively ⁵⁴³.
2441 Additionally, Xiong et al. ⁵⁴⁴ demonstrated that lignosulfonate combined with graphene to obtain hydrogel-based materials was a promising candidate for supercapacitor electrode materials due to its electroactive components. The prepared lignosulfonate-graphene hydrogels achieved the highest capacitance of 549.5 F g⁻¹ at a current density of 1 A g⁻¹ ⁵⁴⁴. In addition, Li et al. ⁵⁴⁵ designed emerging flexible supercapacitors based on redox-active lignosulfonate-functionalized graphene hydrogels (LS-GH) (Figure 32A). The resulting LS-GH electrodes were further fabricated into a flexible solid-state supercapacitor using H₂SO₄–polyvinyl alcohol (PVA) gel as the electrolyte ⁵⁴⁵. The developed supercapacitors provided high capacitance (432 F g⁻¹ in an aqueous electrolyte and 408 Fg⁻¹ using H₂SO₄–polyvinyl alcohol) and excellent mechanical flexibility due to reversible redox charge transfer of quinone groups in lignin (Figure 32B) ⁵⁴⁵. Peng and coworkers ⁴¹⁸ combined the excellent properties of lignin and cellulose to construct a flexible solid-state supercapacitor (FSC). The assembled biomass-based FSC exhibited high specific capacitance (292 F g⁻¹ at a current density of 0.5 A g⁻¹), excellent rate capability, and an outstanding energy density of 17.1 Wh kg⁻¹ at a power density of 324 W kg⁻¹ ⁴¹⁸. Other interesting research works related to the successful utilization of lignin for the development of supercapacitors have also been reported ¹⁵³,⁵⁰⁶,⁵⁴⁶⁻⁵⁵³.

<figure><img src="image_57.png" /></figure>

<figure><img src="image_58.png" /></figure>
2457

2458

2459

2460

2461

2462

2463

2464

2465

2466

2467

2468

2469

2470

2471

2472

2473

2474

2475

2476

2477

2478

2479

2480

2481

2482

2483

2484

2485

2486

2487

2488

2489

2490

2491

2492

2493

2494

2495

2496

2497

2498

2499

2500

2501

**Figure 32:** (A) (a) Illustration depicting the fabrication steps of LS-GH flexible solid-state supercapacitors. (b) Photograph displaying the flexible device. SEM images revealing the internal microstructure under 0.2 MPa pressure, shown at (c) low and (d) high magnifications. (B) Comparative capacitive performances of GH and LS-GH solid-state supercapacitors in PVA–H₂SO₄ gel electrolyte. (a) Specific capacitances under various current densities. (b) CV curves recorded at 200 mV s⁻¹ for different bending angles. (c) Ragone plots illustrating energy and power densities of the LS-GH-based device and reported solid-state devices. (d) Galvanostatic charging/discharging curve of the tandem device featuring three LS-GH units at a current density of 1 A g⁻¹. The inset image displays a photograph of the tandem device. Reproduced with permission from Ref. ⁵⁴, Copyright © 2017 Royal Society of Chemistry.

**Challenges and future directions in lignin based-(bio)sensors** Lignin structural complexity and heterogeneity pose significant challenges in the development of lignin-based sensors. The intricate arrangement of lignin molecules varies depending on the source and processing methods, leading to inconsistencies in sensor performance and reproducibility. Variations in lignin composition, such as the presence of different functional groups and molecular weights, can impact sensor sensitivity and selectivity. Additionally, impurities and contaminants in lignin extracts may interfere with sensing mechanisms, further complicating sensor design and optimization. The extraction and purification of lignin from Lignocellulosic biomass require energy-intensive processes, including chemical treatments and separation techniques. These processes often involve harsh conditions and solvents, leading to high costs and environmental concerns. The scalability of lignin extraction methods is also limited, hindering the large-scale production of lignin-based sensors. Moreover, the purity of lignin extracts can vary depending on the extraction method and source material, affecting sensor performance and reliability. Lignin-based sensors may suffer from stability issues, including degradation, leaching, and fouling, which can compromise sensor performance over time. Lignin is susceptible to degradation under certain environmental conditions, such as exposure to UV radiation, moisture, and high temperatures. Leaching of lignin components into the surrounding environment can result in sensor drift and loss of sensitivity. Furthermore, fouling of sensor surfaces by biomolecules or contaminants can interfere with analyte detection and require frequent sensor maintenance. The mechanisms underlying lignin-analyte interactions are not fully understood, posing challenges in the rational design and optimization of lignin-based sensors. Complex chemical structure and interactions of lignin with analytes involve various physicochemical processes, including adsorption, desorption, and molecular recognition. Further research is needed to elucidate these mechanisms and optimize sensor performance by tailoring lignin properties and sensor configurations.

To address these challenges, future research efforts should focus on fundamental studies to elucidate the structure-property relationships of lignin and its interactions with analytes. This knowledge will enable the rational design of lignin-based sensors with enhanced sensitivity, selectivity, and stability. Multidisciplinary collaboration between researchers from chemistry, materials science, biology, and engineering disciplines is essential to overcome the interdisciplinary challenges associated with lignin-based sensing. By combining expertise from different fields, researchers can develop innovative sensor designs and fabrication techniques tailored to specific applications. Process optimization is critical to improving the scalability and cost-effectiveness of lignin extraction and purification techniques. Advances in green chemistry and sustainable processing methods can minimize energy consumption, waste generation, and environmental impact. By optimizing extraction protocols and refining purification techniques, researchers can produce high-quality lignin extracts with consistent properties for sensor fabrication. Furthermore, the development of lignin-based sensors should be driven by real-world applications, considering factors such as target analytes, detection limits, and environmental conditions.
Application-driven design strategies will ensure that lignin-based sensors meet the practical requirements of end-users and address pressing societal needs, such as environmental monitoring, healthcare diagnostics, and industrial process control. By integrating feedback from stakeholders and end-users, researchers can tailor sensor designs to specific application scenarios and optimize sensor performance in real-world environments.

2507

## 3. Conclusion

2508

Lignocellulosic biomass emerged as a new generation of versatile, renewable, and sustainable materials for various applications, including sensing and biosensing. This review provides an overview of lignocellulosic biomass, including its macromolecular structure, types, and sources. We have discussed the structure, characteristics, and physico-chemical properties of lignocellulosic biomass, emphasizing its major components (cellulose, hemicellulose, and lignin). Additionally, we have highlighted pretreatment methods commonly used to enhance biomass fractionation and accessibility. Despite the remarkable properties of Lignocellulosic biomass, such as abundance, low cost, biodegradability, and biocompatibility, their potential as electrode modifiers for (bio)sensing applications remains underutilized. While some studies have explored the use of hemicellulose in sensor applications, cellulose and lignin have received more attention, with numerous efforts focused on the fabrication of sensors based on these components. Nanocellulose and lignin-based materials offer a versatile platform for the development of fluorescent, optical, and electrical analytical devices, as well as biosensors. These materials show great promise in diverse fields, including health diagnosis, energy storage and production, environmental monitoring, food quality control, forensic analysis, and physical sensing. However, further research and exploration are needed to fully exploit and optimize the potential of Lignocellulosic biomass and their structural biomacromolecules in sensing applications, as well as to overcome the existing challenges in their utilization.

2509

2510

2511

2512

2513

2514

2515

2516

2517

2518

2519

2520

2521

2522

2523

2524

2525

2526

## CRediT authorship contribution statement

2527

2528

2529

2530

2531

2532

2533

2534

2535

2536

2537

**Arnaud Kamdem Tamo** : Conceptualization, Methodology, Investigation, Data curation, Writing – original draft, Writing – review & editing ; **Ingo Doench** : Investigation, Data curation, Writing – review & editing ; **Gullit Deffo** : Investigation, Data curation, Writing – review & editing ; **Sherman Lesly Zambou Jiokeng** : Investigation, Data curation, Writing – review & editing ; **Giscard Doungmo** : Investigation, Data curation, Writing – review & editing ; **Cyrille Ghislain Fotsop** : Data curation, Writing – review & editing ; **Ranil Clément Tonleu Temgoua** : Data curation, Writing – review & editing ; **Evangéline Njanja** : Methodology, Writing – review & editing ; **Ignas Kenfack Tonle** : Methodology, Writing – review & editing ; **Anatoli Serghei** : Methodology, Writing – review & editing, Funding Acquisition ; **Alexandra Montembault** : Methodology, Writing – review & editing, Funding Acquisition ; **Laurent David** : Methodology, Writing – review & editing, Funding Acquisition ; **Anayancy Osorio-Madrazo** : Conceptualization, Methodology, Writing – review & editing, Funding Acquisition

2538

## Funding

2539

This work received financial support from the German Academic Exchange Service (DAAD)..............

2540

## Data availability

2541

No data was used for the research described in the article.
2542 Declaration of competing interest

2543 The authors declare that they have no known competing financial interests or personal relationships that
2544 could have appeared to influence the work reported in this article.

2545 Acknowledgments

2546 The German Academic Exchange Service (DAAD) is gratefully acknowledged for financial
2547 support....................

2548 References

2549 1C. Wang, T. He, H. Zhou, Z. Zhang and C. Lee, *Bioelectron Med*, 2023, **9**, 17.

2550 2M. Javaid, A. Haleem, R. P. Singh, S. Rab and R. Suman, *Sensors International*, 2021, **2**, 100110.

2551 3A. P. F. Turner, *Chem. Soc. Rev.*, 2013, **42**, 3184.

2552 *4Handbook of biosensors and biochips*, John Wiley, Chichester, G. B. Hoboken, N.J, 2007.

2553 5C. Suh and Y.-B. Ko, *IEEE Trans. Consumer Electron.*, 2008, **54**, 1177-1184.

2554 6A. De La Escosura-Muñiz and A. Merkoçi, *ACS Nano*, 2012, **6**, 7556-7583.

2555 7J. Lei and H. Ju, *Chem. Soc. Rev.*, 2012, **41**, 2122.

2556 8Varnakavi. Naresh and N. Lee, *Sensors*, 2021, **21**, 1109.

2557 9H. Golmohammadi, E. Morales-Narváez, T. Naghdi and A. Merkoçi, *Chem. Mater.*, 2017, **29**, 5426-5446.

2558 10 D. Quesada-González and A. Merkoçi, *Biosensors and Bioelectronics*, 2015, **73**, 47-63.

2559 11 G. Deffo, R. Hazarika, M. C. Deussi Ngaha, M. Basumatary, S. Kalita, N. Hussain, E. Njanja, P. Puzari and E. Ngameni, *Anal. Methods*, 2023, **15**, 2456-2466.

2560 12 M. C. Deussi Ngaha, V. Kougoum Tchieda, A. Kamdem Tamo, G. Doungmo, E. Njanja and I. Kenfack Tonle, *Electroanalysis*, 2022, **34**, 1789-1801.

2561 13 A. V. Somba, T. Kamgaing, C. G. Fotsop, G. Deffo, B. W. Nkuigoua, R. F. T. Tagne, K. Y. Tajeu, R. C. T. Temgoua, E. Njanja and I. K. Tonlé, *ChemistrySelect*, 2024, **9**, e202303250.

2562 14 J. Rao, H. Gao, Y. Guan, W. Li and Q. Liu, *Carbohydrate Polymers*, 2019, **208**, 513-520.

2563 15 J.-W. Han, B. Kim, J. Li and M. Meyyappan, *J. Phys. Chem. C*, 2012, **116**, 22094-22097.

2564 16 J. Hu, Y. Wu, Q. Yang, Q. Zhou, L. Hui, Z. Liu, F. Xu and D. Ding, *Carbohydrate Polymers*, 2022, **275**, 118697.

2565 17 X. Gong, C. Fu, N. Alam, Y. Ni, L. Chen, L. Huang and H.-C. Hu, *Industrial Crops and Products*, 2022, **176**, 114412.

2566 18 Q. Zhang, C. An, S. Fan, S. Shi, R. Zhang, J. Zhang, Q. Li, D. Zhang, X. Hu and J. Liu, *Nanotechnology*, 2018, **29**, 285501.

2567 19 H. Abdali, B. Heli and A. Ajji, *Sensors*, 2019, **19**, 5215.

2568 20 E. Núñez-Carmona, A. Bertuna, M. Abbatangelo, V. Sberveglieri, E. Comini and G. Sberveglieri, *Materials Letters*, 2019, **237**, 69-71.

2569 21 C. I. L. Justino, A. C. Duarte and T. A. P. Rocha-Santos, *TrAC Trends in Analytical Chemistry*, 2016, **85**, 36-60.

2570 22 V. Mani, B. Devadas and S.-M. Chen, *Biosensors and Bioelectronics*, 2013, **41**, 309-315.

2571 23 R. Devasenathipathy, V. Mani, S.-M. Chen, S.-T. Huang, T.-T. Huang, C.-M. Lin, K.-Y. Hwa, T.-Y. Chen and B.-J. Chen, *Enzyme and Microbial Technology*, 2015, **78**, 40-45.

2572 24 F. P. Tchoumi, A. K. Tamo, G. Doungmo, C. G. Fotsop, J. C. Kemmegne-Mbouguen and E. Ngameni, *J Appl Electrochem*, 2024, **54**, 1901-1918.
2583

2584

25 C. N. Pecheu, S. L. Z. Jiokeng, A. K. Tamo, G. Doungmo, I. Doench, A. Osorio-Madrazo, I. K. Tonle and E. Ngameni, *Nanomaterials*, 2022, **12**, 2928.

2585

2586

26 J. J. K. Ngouoko, K. Y. Tajeu, C. G. Fotsop, A. K. Tamo, G. Doungmo, R. C. T. Temgoua, T. Kamgaing and I. K. Tonle, *Crystals*, 2022, **12**, 1189.

2587

2588

27 J. J. K. Ngouoko, K. Y. Tajeu, R. C. T. Temgoua, G. Doungmo, I. Doench, A. K. Tamo, T. Kamgaing, A. Osorio-Madrazo and I. K. Tonle, *Materials*, 2022, **15**, 4262.

2589

2590

28 D. V. T. Ebunang, K. Y. Tajeu, C. N. Pecheu, S. L. Z. Jiokeng, A. K. Tamo, I. Doench, A. Osorio-Madrazo, I. K. Tonle and E. Ngameni, *Sensors*, 2022, **22**, 6173.

2591

29 V. S. Bhat, S. S. and G. Hegde, *J. Electrochem. Soc.*, 2020, **167**, 037526.

2592

30 R. Sabo, A. Yermakov, C. T. Law and R. Elhajjar, *j renew mater*, 2016, **4**, 297-312.

2593

31 M. Moyo, J. O. Okonkwo and N. M. Agyei, *Enzyme and Microbial Technology*, 2014, **56**, 28-34.

2594

32 G. Kenne Dedzo, C. Péguy Nanseu-Njiki and E. Ngameni, *Talanta*, 2012, **99**, 478-486.

2595

33 M. Moyo, J. O. Okonkwo and N. M. Agyei, *Electroanalysis*, 2013, **25**, 1946-1954.

2596

2597

34 S. Behera, R. Arora, N. Nandhagopal and S. Kumar, *Renewable and Sustainable Energy Reviews*, 2014, **36**, 91-106.

2598

2599

35 J. Cai, Y. He, X. Yu, S. W. Banks, Y. Yang, X. Zhang, Y. Yu, R. Liu and A. V. Bridgwater, *Renewable and Sustainable Energy Reviews*, 2017, **76**, 309-322.

2600

2601

36 L. G. Djemmoe, T. E. Njanja, M. C. Ngaha Deussi and K. I. Tonle, *Comptes Rendus. Chimie*, 2016, **19**, 841-849.

2602

2603

37 C. P. Nanseu-Njiki, G. K. Dedzo and E. Ngameni, *Journal of Hazardous Materials*, 2010, **179**, 63-71.

2604

2605

38 X. Ren, D. Chen, X. Meng, F. Tang, A. Du and L. Zhang, *Colloids and Surfaces B: Biointerfaces*, 2009, **72**, 188-192.

2606

39 J. Wan, X. Yan, J. Ding and R. Ren, *Sensors and Actuators B: Chemical*, 2010, **146**, 221-225.

2607

40 N. Tripathi, C. D. Hills, R. S. Singh and C. J. Atkinson, *npj Clim Atmos Sci*, 2019, **2**, 35.

2608

2609

41 S. K. Tiwari, M. Bystrzejewski, A. De Adhikari, A. Huczko and N. Wang, *Progress in Energy and Combustion Science*, 2022, **92**, 101023.

2610

42 In *Biorefineries*, Springer London, London, 2010, pp. 115-133.

2611

43 A. K. Tamo, *J. Mater. Chem. B*, 2024, 10.1039.D4TB00397G.

2612

44 F. H. Isikgor and C. R. Becer, *Polym. Chem.*, 2015, **6**, 4497-4559.

2613

2614

45 M. Mujtaba, L. Fernandes Fraceto, M. Fazeli, S. Mukherjee, S. M. Savassa, G. Araujo De Medeiros, A. Do Espírito Santo Pereira, S. D. Mancini, J. Lipponen and F. Vilaplana, *Journal of Cleaner Production*, 2023, **402**, 136815.

2615

2616

2617

46 R. S. Abolore, S. Jaiswal and A. K. Jaiswal, *Carbohydrate Polymer Technologies and Applications*, 2024, **7**, 100396.

2618

2619

47 L. F. Ballesteros, M. Michelin, A. A. Vicente, J. A. Teixeira and M. Â. Cerqueira, *Lignocellulosic Materials and Their Use in Bio-based Packaging*, Springer International Publishing, Cham, 2018.

2620

48 D. Carpenter, T. L. Westover, S. Czernik and W. Jablonski, *Green Chem.*, 2014, **16**, 384-406.

2621

2622

49 G. Izydorczyk, D. Skrzypczak, M. Mironiuk, K. Mikula, M. Samoraj, F. Gil, R. Taf, K. Moustakas and K. Chojnacka, *Science of The Total Environment*, 2024, **923**, 171343.

2623

2624

50 T. Damm, U. Commandeur, R. Fischer, B. Usadel and H. Klose, *Process Biochemistry*, 2016, **51**, 288-296.

2625

51 A. Zoghlami and G. Paës, *Front. Chem.*, 2019, **7**, 874.
2626 52 Y.-H. P. Zhang, *J Ind Microbiol Biotechnol*, 2008, **35**, 367-375.

2627 53 L.-Z. Huang, M.-G. Ma, X.-X. Ji, S.-E. Choi and C. Si, *Front. Bioeng. Biotechnol.*, 2021, **9**, 690773.

2628 54 M. F. Qaseem, H. Shaheen and A.-M. Wu, *Renewable and Sustainable Energy Reviews*, 2021, **144**, 110996.

2630 55 E. Ahmad and K. K. Pant, in *Waste Biorefinery*, Elsevier, 2018, pp. 409-444.

2631 56 O. Y. Abdelaziz, D. P. Brink, J. Prothmann, K. Ravi, M. Sun, J. García-Hidalgo, M. Sandahl, C. P. Hulteberg, C. Turner, G. Lidén and M. F. Gorwa-Grauslund, *Biotechnology Advances*, 2016, **34**, 1318-1346.

2634 57 S. Lee, M. Kang, J.-H. Bae, J.-H. Sohn and B. H. Sung, *Front. Bioeng. Biotechnol.*, 2019, **7**, 209.

2635 58 M. M. Alam, A. Greco, Z. Rajabimashhadi and C. Esposito Corcione, *Cleaner Materials*, 2024, **13**, 100253.

2637 59 M. Martín, M. Taifouris and G. Galán, *Bioresource Technology*, 2023, **385**, 129397.

2638 60 G. Velvizhi, P. J. Jacqueline, N. P. Shetti, L. K. G. Mohanakrishna and T. M. Aminabhavi, *Journal of Environmental Management*, 2023, **345**, 118527.

2640 61 M. K. Awasthi, T. Sar, S. C. Gowd, K. Rajendran, V. Kumar, S. Sarsaiya, Y. Li, R. Sindhu, P. Binod, Z. Zhang, A. Pandey and M. J. Taherzadeh, *Fuel*, 2023, **342**, 127790.

2642 62 T. Raj, K. Chandrasekhar, A. Naresh Kumar and S.-H. Kim, *Renewable and Sustainable Energy Reviews*, 2022, **158**, 112130.

2644 63 E. Thomchick, M. Jacobson and K. Ruamsook, *EFB Bioeconomy Journal*, 2024, **4**, 100068.

2645 64 S. Brethauer, R. L. Shahab and M. H. Studer, *Appl Microbiol Biotechnol*, 2020, **104**, 5201-5212.

2646 65 D. M. Alonso, S. G. Wettstein and J. A. Dumesic, *Chem. Soc. Rev.*, 2012, **41**, 8075.

2647 66 V. B. Agbor, N. Cicek, R. Sparling, A. Berlin and D. B. Levin, *Biotechnology Advances*, 2011, **29**, 675-685.

2649 67 R. Huang, R. Su, W. Qi and Z. He, *Bioenerg. Res.*, 2011, **4**, 225-245.

2650 68 A. K. Tamo, L. D. W. Djouonkep and N. B. S. Selabi, *International Journal of Biological Macromolecules*, 2024, **270**, 132123.

2652 69 E. Calcio Gaudino, G. Cravotto, M. Manzoli and S. Tabasso, *Green Chem.*, 2019, **21**, 1202-1235.

2653 70 Z. Su, Y. Yang, Q. Huang, R. Chen, W. Ge, Z. Fang, F. Huang and X. Wang, *Progress in Materials Science*, 2022, **125**, 100917.

2655 71 H. M. C. De Azeredo, M. F. Rosa, M. De Sá, M. Souza Filho and K. W. Waldron, in *Advances in Biorefineries*, Elsevier, 2014, pp. 819-874.

2657 72 H. Zhang, X. Lin, X. Cao, Y. Wang, J. Wang and Y. Zhao, *Bioactive Materials*, 2024, **33**, 355-376.

2658 73 R. Shakoor, N. Hussain, H. Bashir and M. H. Ashraf, in *Plant Biomass Applications*, Elsevier, 2024, pp. 185-208.

2660 74 M. Yadav, G. Goel, F. L. Hatton, M. Bhagat, S. K. Mehta, R. K. Mishra and N. Bhojak, *Current Research in Green and Sustainable Chemistry*, 2021, **4**, 100153.

2662 75 C. Bejenaru, A. Radu, A.-E. Segneanu, A. Biță, M. V. Ciocîlteu, G. D. Mogoșanu, I. A. Bradu, T. Vlase, G. Vlase and L. E. Bejenaru, *Polymers*, 2024, **16**, 1182.

2664 76 K. Kucharska, P. Rybarczyk, I. Hołowacz, R. Łukajtis, M. Glinka and M. Kamiński, *Molecules*, 2018, **23**, 2937.

2666 77 E. Albers, E. Malmhäll-Bah, J. Olsson, M. Sterner, J. J. Mayers, G. M. Nylund, K. Rupar-Gadd, M. Abdollahi, S. Cvijetinovic, U. Welander, U. Edlund, H. Pavia and I. Undeland, *Algal Research*, 2021, **55**, 102261.
2669 78 A. Shukla, D. Kumar, M. Girdhar, A. Kumar, A. Goyal, T. Malik and A. Mohan, *Biotechnol Biofuels*, 2023, **16**, 44.

2671 79 C. Veluchamy, A. S. Kalamdhad and B. H. Gilroyed, in *Handbook of Environmental Materials Management*, ed. C. M. Hussain, Springer International Publishing, Cham, 2018, pp. 1–19.

2673 80 A. K. Kumar and S. Sharma, *Bioresour. Bioprocess.*, 2017, **4**, 7.

2674 81 H. Rezaei, M. Tajilrou, J. S. Lee, K. Singaraveloo, A. Lau and S. Sokhansanj, *Particuology*, 2024, **86**, 182–187.

2676 82 V. Dhyani and T. Bhaskar, *Renewable Energy*, 2018, **129**, 695–716.

2677 83 J. S. Kim, Y. Y. Lee and T. H. Kim, *Bioresource Technology*, 2016, **199**, 42–48.

2678 84 X. Chen, R. Zhai, K. Shi, Y. Yuan, B. E. Dale, Z. Gao and M. Jin, *Industrial Crops and Products*, 2018, **124**, 719–725.

2680 85 R. Kataria, R. Ruhal, R. Babu and S. Ghosh, *Chemical Engineering Journal*, 2013, **230**, 36–47.

2681 86 C. Arce and L. Kratky, *iScience*, 2022, **25**, 104610.

2682 87 D. Fougere, K. Clarke, Y. Zhao and K. Li, *Biomass and Bioenergy*, 2015, **80**, 17–29.

2683 88 Y. Su, X. Yu, Y. Sun, G. Wang, H. Chen and G. Chen, *Sci Rep*, 2018, **8**, 5385.

2684 89 I. G. Audu, N. Brosse, H. Winter, A. Hoffmann, M. Bremer, S. Fischer and M.-P. Laborie, *Polymers*, 2018, **10**, 619.

2686 90 Y.-C. Sun, X.-N. Liu, T.-T. Wang, B.-L. Xue and R.-C. Sun, *ACS Sustainable Chem. Eng.*, 2019, **7**, 13062–13072.

2688 91 A. M. Asim, M. Uroos and N. Muhammad, *RSC Adv.*, 2020, **10**, 44003–44014.

2689 92 W. Zhao, R. Yang, Y. Zhang and L. Wu, *Green Chem.*, 2012, **14**, 3352.

2690 93 T. Pielhop, J. Amgarten, P. R. Von Rohr and M. H. Studer, *Biotechnol Biofuels*, 2016, **9**, 152.

2691 94 H. Lv, L. Yan, M. Zhang, Z. Geng, M. Ren and Y. Sun, *Chem Eng & Technol*, 2013, **36**, 1899–1906.

2692 95 A. Kallioinen, A. Vaari, M. Rättö, J. Konn, M. Siika-aho and L. Viikari, *Journal of Biotechnology*, 2003, **103**, 67–76.

2694 96 L. Lin, R. Yan, Y. Liu and W. Jiang, *Bioresource Technology*, 2010, **101**, 8217–8223.

2695 97 M. Si, D. Liu, M. Liu, X. Yan, C. Gao, L. Chai and Y. Shi, *Bioresource Technology*, 2019, **272**, 275–280.

2697 98 M. Taylor, H. Alabdrabalameer and V. Skoulou, *Sustainability*, 2019, **11**, 3604.

2698 99 C.-Y. Ma, L.-H. Xu, Q. Sun, X.-J. Shen, J.-L. Wen and T.-Q. Yuan, *Chemical Engineering Journal*, 2022, **450**, 138315.

2700 100 Y. Feng, L. Tao, Y. He, Q. Jin, C. Kuai, Y. Zheng, M. Li, Q. Hou, Z. Zheng, F. Lin and H. Huang, *J. Mater. Chem. A*, 2019, **7**, 26954–26965.

2701 101 H. Yu, G. Guo, X. Zhang, K. Yan and C. Xu, *Bioresource Technology*, 2009, **100**, 5170–5175.

2703 102 C. Dupont, R. Chiriac, G. Gauthier and F. Toche, *Fuel*, 2014, **115**, 644–651.

2704 103 C. Mayer-Laigle, N. Blanc, R. K. Rajaonarivony and X. Rouau, *Bioengineering*, 2018, **5**, 41.

2705 104 D. E. Priyanto, S. Ueno, K. Hashida and H. Kasai, *Advanced Powder Technology*, 2017, **28**, 1660–1667.

2707 105 J. S. Tumuluru and D. J. Heikkila, *Bioengineering*, 2019, **6**, 12.

2708 106 P. Karinkanta, A. Ämmälä, M. Illikainen and J. Niinimäki, *Biomass and Bioenergy*, 2018, **113**, 31–44.

2710 107 Z. Cui, J. Lin, C. Zhan, J. Wu, S. Shen, J. Si and Q. Wang, *Journal of Biomaterials Science, Polymer Edition*, 2020, **31**, 561–577.
2712 108 J.-A. Choi, J.-H. Hwang, B. A. Dempsey, R. A. I. Abou-Shanab, B. Min, H. Song, D. S. Lee, J. R. Kim, Y. Cho, S. Hong and B.-H. Jeon, *Energy Environ. Sci.*, 2011, **4**, 3513.

2713 109 X. Liu, H. Sun, T. Mu, M. L. Fauconnier and M. Li, *Food Chemistry*, 2023, **413**, 135675.

2714 110 Z. Pang, P. Wang and C. Dong, *Cellulose*, 2018, **25**, 7053–7064.

2715 111 L. Desrochers, D. Puttock and M. Ryans, *Biomass and Bioenergy*, 1993, **5**, 401–411.

2716 112 J. Viell, H. Wulfhorst, T. Schmidt, U. Commandeur, R. Fischer, A. Spiess and W. Marquardt, *Bioresource Technology*, 2013, **146**, 144–151.

2717 113 W. Stelte, A. R. Sanadi, L. Shang, J. K. Holm, J. Ahrenfeldt and U. B. Henriksen, *BioRes*, 2012, **7**, 4451–4490.

2718 114 P. Basu, *Biomass gasification, pyrolysis, and torrefaction: practical design and theory*, Academic Press is and imprint of Elsevier, London, United Kingdom; San Diego, CA, United States, Third edition., 2018.

2719 115 T. G. Bridgeman, J. M. Jones, I. Shield and P. T. Williams, *Fuel*, 2008, **87**, 844–856.

2720 116 J. M. C. Ribeiro, R. Godina, J. C. D. O. Matias and L. J. R. Nunes, *Sustainability*, 2018, **10**, 2323.

2721 117 M. Phanphanich and S. Mani, *Bioresource Technology*, 2011, **102**, 1246–1253.

2722 118 A. Duque, P. Manzanares and M. Ballesteros, *Renewable Energy*, 2017, **114**, 1427–1441.

2723 119 D. Konan, E. Koffi, A. Ndao, E. C. Peterson, D. Rodrigue and K. Adjallé, *Energies*, 2022, **15**, 3002.

2724 120 Y.-S. Cheng, Y. Zheng, C. W. Yu, T. M. Dooley, B. M. Jenkins and J. S. VanderGheynst, *Appl. Biochem Biotechnol*, 2010, **162**, 1768–1784.

2725 121 H. Xu, B. Li and X. Mu, *Ind. Eng. Chem. Res.*, 2016, **55**, 8691–8705.

2726 122 A. Shahbazi and B. Zhang, in *Bioalcohol Production*, Elsevier, 2010, pp. 143–158.

2727 123 R. Harun and M. K. Danquah, *Process Biochemistry*, 2011, **46**, 304–309.

2728 124 M. H. Rubiyah, K. Melethil, S. Varghese, M. Kurian, S. Babu, L. Jojo and B. Thomas, *Carbohydrate Polymer Technologies and Applications*, 2023, **6**, 100374.

2729 125 B.-W. Koo, H.-Y. Kim, N. Park, S.-M. Lee, H. Yeo and I.-G. Choi, *Biomass and Bioenergy*, 2011, **35**, 1833–1840.

2730 126 V. A. Barbash, O. V. Yaschenko and O. M. Shniruk, *Nanoscale Res Lett*, 2017, **12**, 241.

2731 127 A. Brandt, J. Gräsvik, J. P. Hallett and T. Welton, *Green Chem.*, 2013, **15**, 550.

2732 128 Z. Zhou, D. Ouyang, D. Liu and X. Zhao, *Bioresource Technology*, 2023, **367**, 128208.

2733 129 Z. Yuan, G. E. Klinger, S. Nikafshar, Y. Cui, Z. Fang, M. Alherech, S. Goes, C. Anson, S. K. Singh, B. Bals, D. B. Hodge, M. Nejad, S. S. Stahl and E. L. Hegg, *ACS Sustainable Chem. Eng.*, 2021, **9**, 1118–1127.

2734 130 C. G. Fotsop, D. R. Tchuifon Tchuifon, P. A. N. Kouteu, K. L. T. Nguena, A. K. Tamo, D. N. Dongmo, S. G. M. Mafo, F. H. K. Djioko, R. M. Mouangue and I. K. Tonle, *Biomass Conv. Bioref.*, DOI:10.1007/s13399-024-05331-9.

2735 131 D. Z. Haddis, M. Chae, J. Asomaning and D. C. Bressler, *Carbohydrate Polymers*, 2024, **323**, 121460.

2736 132 K. C. Badgujar, R. Dange and B. M. Bhanage, *Journal of the Indian Chemical Society*, 2021, **98**, 100018.

2737 133 A. Demirbaş, *Energy Conversion and Management*, 2001, **42**, 279–294.

2738 134 F. Teymouri, L. Laureano-Perez, H. Alizadeh and B. E. Dale, *Bioresource Technology*, 2005, **96**, 2014–2018.
2754

2755

135 M. T. Holtzapple, J. E. Lundeen, R. Sturgis, J. E. Lewis and B. E. Dale, *Appl Biochem Biotechnol*, 1992, **34-35**, 5-21.

2756

2757

136 J. S. Schilling, J. Ai, R. A. Blanchette, S. M. Duncan, T. R. Filley and U. W. Tschirner, *Bioresource Technology*, 2012, **116**, 147-154.

2758

2759

137 F. Amalina, A. S. A. Razak, S. Krishnan, H. Sulaiman, A. W. Zularisam and M. Nasrullah, *Journal of Hazardous Materials Advances*, 2022, **7**, 100134.

2760

138 G. Kabir and B. H. Hameed, *Renewable and Sustainable Energy Reviews*, 2017, **70**, 945-967.

2761

2762

139 J. Baruah, B. K. Nath, R. Sharma, S. Kumar, R. C. Deka, D. C. Baruah and E. Kalita, *Front. Energy Res.*, 2018, **6**, 141.

2763

140 X. Liu, Y. Jiang, C. Qin, S. Yang, X. Song, S. Wang and K. Li, *Cellulose*, 2018, **25**, 7065-7078.

2764

141 C. Mayer-Laigle, R. K. Rajaonarivony, N. Blanc and X. Rouau, *Bioengineering*, 2018, **5**, 50.

2765

2766

142 T. J. Mason and J. P. Lorimer, *Applied Sonochemistry: Uses of Power Ultrasound in Chemistry and Processing*, Wiley, 1st edn., 2002.

2767

143 J. Luo, Z. Fang and R. L. Smith, *Progress in Energy and Combustion Science*, 2014, **41**, 56-93.

2768

144 M. J. Bussemaker and D. Zhang, *Ind. Eng. Chem. Res.*, 2013, **52**, 3563-3580.

2769

2770

145 L. Pari, V. Civitarese, A. D. Giudice, A. Assirelli, R. Spinelli and E. Santangelo, *Biomass and Bioenergy*, 2013, **51**, 169-176.

2771

2772

146 R. Keefe, N. Anderson, J. Hogland and K. Muhlenfeld, in *Cellulosic Energy Cropping Systems*, ed. D. L. Karlen, Wiley, 1st edn., 2014, pp. 251-279.

2773

2774

147 H. Gilvari, C. H. H. Van Battum, S. A. Van Dijk, W. De Jong and D. L. Schott, *Particuology*, 2021, **57**, 146-156.

2775

2776

148 J. Shankar Tumuluru, S. Sokhansanj, J. R. Hess, C. T. Wright and R. D. Boardman, *Industrial Biotechnology*, 2011, **7**, 384-401.

2777

149 J. Tripathi, T. L. Richard, B. Memis, A. Demirci and D. Ciolkosz, *Biomass*, 2022, **2**, 264-278.

2778

150 H. Choi and D. Pak, *Journal of Energy Engineering*, 2015, **24**, 1-5.

2779

151 F. Sher, A. Yaqoob, F. Saeed, S. Zhang, Z. Jahan and J. J. Klemeš, *Energy*, 2020, **209**, 118444.

2780

152 H. Li, Y. Qu, Y. Yang, S. Chang and J. Xu, *Bioresource Technology*, 2016, **199**, 34-41.

2781

2782

153 C. Lai, Z. Zhou, L. Zhang, X. Wang, Q. Zhou, Y. Zhao, Y. Wang, X.-F. Wu, Z. Zhu and H. Fong, *Journal of Power Sources*, 2014, **247**, 134-141.

2783

154 X. Chen, H. Li, S. Sun, X. Cao and R. Sun, *Sci Rep*, 2016, **6**, 39354.

2784

2785

155 C. A. Eckert and C. T. Trinh, Eds., *Biotechnology for biofuel production and optimization*, Elsevier, Amsterdam; Boston, 2016.

2786

2787

156 T. Taflick, L. A. Schwendler, S. M. L. Rosa, C. I. D. Bica and S. M. B. Nachtigall, *International Journal of Biological Macromolecules*, 2017, **101**, 553-561.

2788

157 R. Rohaizu and W. D. Wanrosli, *Ultrasonics Sonochemistry*, 2017, **34**, 631-639.

2789

2790

158 M. Smyth, A. García, C. Rader, E. J. Foster and J. Bras, *Industrial Crops and Products*, 2017, **108**, 257-266.

2791

159 X. Zhao, K. Cheng and D. Liu, *Appl Microbiol Biotechnol*, 2009, **82**, 815-827.

2792

160 Z. Zhou, F. Lei, P. Li and J. Jiang, *Biotech & Bioengineering*, 2018, **115**, 2683-2702.

2793

2794

161 F.-L. Wang, S. Li, Y.-X. Sun, H.-Y. Han, B.-X. Zhang, B.-Z. Hu, Y.-F. Gao and X.-M. Hu, *RSC Adv.*, 2017, **7**, 47990-47998.

2795

2796

162 M. Zavrel, D. Bross, M. Funke, J. Büchs and A. C. Spiess, *Bioresource Technology*, 2009, **100**, 2580-2587.
2797 163 H. Palonen, A. B. Thomsen, M. Tenkanen, A. S. Schmidt and L. Viikari, *ABAB*, 2004, **117**, 01–18.

2798 164 C. Schacht, C. Zetzl and G. Brunner, *The Journal of Supercritical Fluids*, 2008, **46**, 299–321.

2799 165 I. Lázár and I. Fábián, *Gels*, 2016, **2**, 26.

2800 166 N. Narayanaswamy, A. Faik, D. J. Goetz and T. Gu, *Bioresource Technology*, 2011, **102**, 6995–7000.

2801 167 C. Park and J. Lee, *Green Chem.*, 2020, **22**, 2628–2642.

2802 168 A. R. C. Morais, A. M. Da Costa Lopes and R. Bogel-Lukasik, *Chem. Rev.*, 2015, **115**, 3–27.

2803 169 S. Zhuo, X. Yan, D. Liu, M. Si, K. Zhang, M. Liu, B. Peng and Y. Shi, *Biotechnol Biofuels*, 2018, **11**, 146.

2804 170 G. Janusz, A. Pawlik, J. Sulej, U. Świderska-Burek, A. Jarosz-Wilkołazka and A. Paszczyński, *FEMS Microbiology Reviews*, 2017, **41**, 941–962.

2805 171 S. Mishra, P. K. Singh, S. Dash and R. Pattnaik, *3 Biotech*, 2018, **8**, 458.

2806 172 C. Wan and Y. Li, *Biotechnology Advances*, 2012, **30**, 1447–1457.

2807 173 W. Y. Cheah, R. Sankaran, P. L. Show, Tg. N. B. Tg. Ibrahim, K. W. Chew, A. Culaba and J.-S. Chang, *Biofuel Res. J.*, 2020, **7**, 1115–1127.

2808 174 W. R. De Souza, in *Sustainable Degradation of Lignocellulosic Biomass - Techniques, Applications and Commercialization*, ed. A. Chandel, InTech, 2013.

2809 175 O. M. Buraimoh, M. O. Ilori, O. O. Amund, F. C. Michel and S. K. Grewal, *International Biodeterioration & Biodegradation*, 2015, **104**, 186–193.

2810 176 B. Tsegaye, C. Balomajumder and P. Roy, *3 Biotech*, 2018, **8**, 447.

2811 177 J. Pérez, J. Muñoz-Dorado, T. De La Rubia and J. Martínez, *Int Microbiol*, 2002, **5**, 53–63.

2812 178 A. Kamdem Tamo, I. Doench, A. Morales Helguera, D. Hoenders, A. Walther and A. O. Madrazo, *Polymers*, 2020, **12**, 1522.

2813 179 T. B. Vinzant, W. S. Adney, S. R. Decker, J. O. Baker, M. T. Kinter, N. E. Sherman, J. W. Fox and M. E. Himmel, *ABAB*, 2001, **91–93**, 99–108.

2814 180 R. Kumar, S. Singh and O. V. Singh, *J Ind Microbiol Biotechnol*, 2008, **35**, 377–391.

2815 181 C.-R. Lee, B. H. Sung, K.-M. Lim, M.-J. Kim, M. J. Sohn, J.-H. Bae and J.-H. Sohn, *Sci Rep*, 2017, **7**, 4428.

2816 182 C.-T. Tsai and A. Meyer, *Molecules*, 2014, **19**, 19390–19406.

2817 183 M. Meena, A. Zehra, M. K. Dubey, M. Aamir and R. S. Upadhyay, in *New and Future Developments in Microbial Biotechnology and Bioengineering*, Elsevier, 2018, pp. 167–186.

2818 184 R. Datta, A. Kelkar, D. Baraniya, A. Molaei, A. Moulick, R. Meena and P. Formanek, *Sustainability*, 2017, **9**, 1163.

2819 185 K. Umezawa, M. Niikura, Y. Kojima, B. Goodell and M. Yoshida, *PLoS ONE*, 2020, **15**, e0243984.

2820 186 M. Monrroy, I. Ortega, M. Ramírez, J. Baeza and J. Freer, *Enzyme and Microbial Technology*, 2011, **49**, 472–477.

2821 187 Q. Guo, X. Chen and H. Liu, *Fuel*, 2012, **94**, 551–555.

2822 188 D. Gera, M. P. Mathur, M. C. Freeman and A. Robinson, *Energy Fuels*, 2002, **16**, 1523–1532.

2823 189 Z. Wang, C. J. Lim, J. R. Grace, H. Li and M. R. Parise, *Bioresource Technology*, 2017, **244**, 281–288.

2824 190 B. C. Vidal, B. S. Dien, K. C. Ting and V. Singh, *Appl Biochem Biotechnol*, 2011, **164**, 1405–1421.

2825 191 Y. Shastri, A. Hansen, L. Rodríguez and K. C. Ting, Eds., *Engineering and Science of Biomass Feedstock Production and Provision*, Springer New York, New York, NY, 2014.
2840 192 P. S. Lam, S. Sokhansanj, X. Bi, C. J. Lim, L. J. Naimi, M. Hoque, S. Mani, A. R. Womac, S. Narayan, and X. P. Ye, *Applied Engineering in Agriculture*, 2008, **24**, 351–358.

2841 193 H. Rezaei, C. J. Lim, A. Lau and S. Sokhansanj, *Powder Technology*, 2016, **301**, 737–746.

2843 194 Z. Liu, B. Mi, Z. Jiang, B. Fei, Z. Cai and X. Liu, *Renewable Energy*, 2016, **86**, 1–7.

2844 195 J. Koppejan and S. Van Loo, Eds., *The Handbook of Biomass Combustion and Co-firing*, Routledge, 2012.

2846 196 S. Basu, U. S. Shivhare and A. S. Mujumdar, *Drying Technology*, 2006, **24**, 917–930.

2847 197 E. E. Thybring, S. V. Glass and S. L. Zelinka, *Forests*, 2019, **10**, 704.

2848 198 A. Kamdem Tamo, I. Doench, L. Walter, A. Montembault, G. Sudre, L. David, A. Morales-Helguera, M. Selig, B. Rolauffs, A. Bernstein, D. Hoenders, A. Walther and A. Osorio-Madrazo, *Polymers*, 2021, **13**, 1663.

2851 199 S. Marquez-Bravo, I. Doench, P. Molina, F. E. Bentley, A. K. Tamo, R. Passieux, F. Lossada, L. David and A. Osorio-Madrazo, *Polymers*, 2021, **13**, 1563.

2853 200 M. E. Jawerth, C. J. Brett, C. Terrier, P. T. Larsson, M. Lawoko, S. V. Roth, S. Lundmark and M. Johansson, *ACS Appl. Polym. Mater.*, 2020, **2**, 668–676.

2855 201 P. E. Mason, L. I. Darvell, J. M. Jones and A. Williams, *Energy Fuels*, 2016, **30**, 2158–2163.

2856 202 S. V. Vassilev, D. Baxter, L. K. Andersen and C. G. Vassileva, *Fuel*, 2010, **89**, 913–933.

2857 203 S. V. Vassilev, C. G. Vassileva, Y.-C. Song, W.-Y. Li and J. Feng, *Fuel*, 2017, **208**, 377–409.

2858 204 O. Olatunji, S. Akinlabi, A. Oluseyi, M. Peter and N. Madushele, *IOP Conf. Ser.: Mater. Sci. Eng.*, 2018, **413**, 012054.

2860 205 D. K. Sarkar, *Thermal power plant: design and operation*, Elsevier, Amsterdam, 2015.

2861 206 A. I. Lawal, A. E. Aladejare, M. Onifade, S. Bada and M. A. Idris, *Int J Coal Sci Technol*, 2021, **8**, 124–140.

2863 207 A. Bichot, M. Lerosty, L. Geirnaert, V. Méchin, H. Carrère, N. Bernet, J.-P. Delgenès and D. García-Bernet, *Molecules*, 2019, **24**, 3885.

2865 208 M. C. D. Ngaha, E. Njanja, G. Doungmo, A. Tamo Kamdem and I. K. Tonle, *International Journal of Biomaterials*, 2019, **2019**, 1–18.

2867 209 G. F. K. Nindjio, R. F. T. Tagne, S. L. Z. Jiokeng, C. G. Fotsop, A. Bopda, G. Doungmo, R. C. T. Temgoua, I. Doench, E. T. Njoyim, A. K. Tamo, A. Osorio-Madrazo and I. K. Tonle, *Polymers*, 2022, **14**, 3776.

2870 210 L. D. W. Djouonkep, A. K. Tamo, I. Doench, N. B. S. Selabi, E. M. Ilunga, A. R. K. Lenwoue, M. Gauthier, Z. Cheng and A. Osorio-Madrazo, *Molecules*, 2022, **27**, 325.

2872 211 L. Djouonkep, A. Tchameni, N. Selabi, A. Tamo, I. Doench, Z. Cheng, M. Gauthier, B. Xie and A. Osorio-Madrazo, *IJMS*, 2022, **23**, 8967.

2874 212 M. H. Tanis, O. Wallberg, M. Galbe and B. Al-Rudainy, *Molecules*, 2023, **29**, 98.

2875 213 Z. Sun, B. Fridrich, A. De Santi, S. Elangovan and K. Barta, *Chem. Rev.*, 2018, **118**, 614–678.

2876 214 A. B. Gunjal, N. N. Patil and S. S. Shinde, in *Enzymes in Degradation of the Lignocellulosic Wastes*, Springer International Publishing, Cham, 2020, pp. 41–53.

2878 215 A. B. Gunjal, N. N. Patil and S. S. Shinde, in *Enzymes in Degradation of the Lignocellulosic Wastes*, Springer International Publishing, Cham, 2020, pp. 55–70.

2880 216 D. Kim, J. M. Kim, Y. Jeon, J. Lee, J. Oh, W. Hooch Antink, D. Kim and Y. Piao, *Sensors and Actuators B: Chemical*, 2018, **259**, 50–58.
2882 217 T. Sha, X. Li, J. Liu, M. Sun, N. Wang, X. Bo, Y. Guo, Z. Hu and M. Zhou, *Sensors and Actuators B: Chemical*, 2018, **277**, 195-204.

2883 218 J. Poisson and K. Zhang, *Acc. Mater. Res.*, 2024, **5**, 920-932.

2884 219 D. O. Dorohoi, M. Postolache, C. D. Nechifor, D. G. Dimitriu, R. M. Albu, I. Stoica and A. I. Barzic, *Molecules*, 2023, **28**, 2955.

2887 220 H. Liu, J. Ding, K. Zhang and L. Ding, *TrAC Trends in Analytical Chemistry*, 2019, **118**, 315-337.

2888 221 Y. Shi, W. Li, X. Hu, X. Zhang, X. Huang, Z. Li, X. Zhai, T. Shen, J. Shi, Y. He and X. Zou, *Food Chemistry*, 2024, **434**, 137260.

2889 222 V. Veeramani, M. Sivakumar, S.-M. Chen, R. Madhu, H. R. Alamri, Z. A. Alothman, Md. S. A. Hossain, C.-K. Chen, Y. Yamauchi, N. Miyamoto and K. C.-W. Wu, *RSC Adv.*, 2017, **7**, 45668-45675.

2892 223 S. Long, Y. Feng, F. He, J. Zhao, T. Bai, H. Lin, W. Cai, C. Mao, Y. Chen, L. Gan, J. Liu, M. Ye, X. Zeng and M. Long, *Nano Energy*, 2021, **85**, 105973.

2894 224 L. Durai, A. Gopalakrishnan and S. Badhulika, *Analytica Chimica Acta*, 2021, **1169**, 338598.

2895 225 E. Njanja, S. F. Mbokou, M. Pontie, M. Nacef and I. K. Tonle, *SN Appl. Sci.*, 2019, **1**, 513.

2896 226 Z. Deng, Z. Wu, H. Rokni, Z. Yin, J. Lin, H. Zhang and S. Cheraghi, *Chemosphere*, 2022, **309**, 136568.

2898 227 W. Hu, S. Chen, L. Liu, B. Ding and H. Wang, *Sensors and Actuators B: Chemical*, 2011, **157**, 554-559.

2900 228 C. Hu, X. Bai, Y. Wang, W. Jin, X. Zhang and S. Hu, *Anal. Chem.*, 2012, **84**, 3745-3750.

2901 229 F. Yang, W. Fu, J. Liu, W. Ding and W. Sun, *International Journal of Electrochemical Science*, 2023, **18**, 100364.

2903 230 Ş. F. Küçükkayar, V. Şimşek, M. O. Caglayan, Z. Üstündağ and S. Şahin, *Microchemical Journal*, 2023, **193**, 109023.

2905 231 X. Cui, Y. Zhang, Z. Chen, H. Xiao, R. Xiong and C. Huang, *International Journal of Biological Macromolecules*, 2023, **252**, 126431.

2907 232 I. K. Tonlé, S. Letaief, E. Ngameni, A. Walcarius and C. Detellier, *Electroanalysis*, 2011, **23**, 245-252.

2909 233 T. B. Tran, S. J. Son and J. Min, *BioChip J*, 2016, **10**, 318-330.

2910 234 N. Reta, C. P. Saint, A. Michelmore, B. Prieto-Simon and N. H. Voelcker, *ACS Appl. Mater. Interfaces*, 2018, **10**, 6055-6072.

2912 235 H. Liu, J. Ding, K. Zhang and L. Ding, *TrAC Trends in Analytical Chemistry*, 2019, **118**, 315-337.

2913 236 C. B. Njine-Bememba, G. K. Dedzo, C. P. Nanseu-Njiki and E. Ngameni, *Holzforschung*, 2015, **69**, 347-356.

2915 237 B. Ngouné, M. Pengou, C. P. Nanseu-Njiki and E. Ngameni, *Corrosion Engineering, Science and Technology*, 2020, **55**, 138-144.

2917 238 B. Ngouné, M. Pengou, A. M. Nouteza, C. P. Nanseu-Njiki and E. Ngameni, *ACS Omega*, 2019, **4**, 9081-9091.

2919 239 S. F. Mbokou, M. Pontié, J.-P. Bouchara, F. M. M. Tchieno, E. Njanja, A. Mogni, P. Y. Pontalier and I. K. Tonle, *International Journal of Electrochemistry*, 2016, **2016**, 1-10.

2921 240 K. Radotić, D. Djikanović, J. Simonović Radosavljević, N. Jović-Jovičić and Z. Mojović, *Journal of Electroanalytical Chemistry*, 2020, **862**, 114010.

2923 241 C.-M. Kuan, R. L. York and C.-M. Cheng, *Sci Rep*, 2015, **5**, 18570.
2924 242 Y. Zhang, F. Wen, Z. Huang, J. Tan, Z. Zhou, K. Yuan and H. Wang, *Journal of Electroanalytical Chemistry*, 2017, **806**, 150–157.

2925 243 D. Chen, H. Zhou, H. Li, J. Chen, S. Li and F. Zheng, *Sci Rep*, 2017, **7**, 14985.

2927 244 M. Li, Y. Qi, Y. Ding, Q. Zhao, J. Fei and J. Zhou, *Sensors and Actuators B: Chemical*, 2012, **168**, 329–335.

2929 245 X. Li, H. Li, T. Liu, Y. Hei, M. Hassan, S. Zhang, J. Lin, T. Wang, X. Bo, H.-L. Wang, H. Li and M. Zhou, *Sensors and Actuators B: Chemical*, 2018, **255**, 3248–3256.

2931 246 S. Yallappa, M. Shivakumar, K. L. Nagashree, M. S. Dharmaprakash, A. Vinu and G. Hegde, *J. Electrochem. Soc.*, 2018, **165**, H614–H619.

2933 247 J. J. Arroyo-Gómez, D. Villarroel-Rocha, K. C. De Freitas-Araújo, C. A. Martínez-Huitle and K. Sapag, *Journal of Electroanalytical Chemistry*, 2018, **822**, 171–176.

2935 248 N. Jayarambabu, N. V. S. S. S. Rao, M. K. C. Sivalenka, K. Saraswathi, B. S. Naick, N. Anitha and T. V. Rao, *Diamond and Related Materials*, 2024, **144**, 110959.

2937 249 B. Zhang, X. Li, Z. Wang, H. Ren, J. Wang, Q. Chen, Y. Cai, K. Quan, M. Liu, M. Pan and G. Fang, *Talanta*, 2024, **277**, 126395.

2939 250 O. Fatibello-Filho, *Talanta*, 2001, **55**, 685–692.

2940 251 I. Cruz Vieira, *Talanta*, 2000, **52**, 681–689.

2941 252 O. Fatibello-Filho and I. Cruz Vieira, *Fresenius' Journal of Analytical Chemistry*, 2000, **368**, 338–343.

2943 253 S. Liu, T. Han, Z. Wang, T. Fei and T. Zhang, *Electroanalysis*, 2019, **31**, 527–534.

2944 254 X. Qiu and S. Hu, *Materials*, 2013, **6**, 738–781.

2945 255 O. J. Rojas, Ed., *Cellulose Chemistry and Properties: Fibers, Nanocelluloses and Advanced Materials*, Springer International Publishing, Cham, 2016, vol. 271.

2947 256 V. K. Thakur, *Cellulose-based graft copolymers: structure and chemistry*, CRC Press, Boca Raton, Florida, 2015.

2949 257 P. Samyn and A. Osorio-Madrazo, in *Handbook of Nanofibers*, eds. A. Barhoum, M. Bechelany and A. S. H. Makhlouf, Springer International Publishing, Cham, 2019, pp. 287–321.

2951 258 A. Osorio-Madrazo, M. Eder, M. Rueggeberg, J. K. Pandey, M. J. Harrington, Y. Nishiyama, J.-L. Putaux, C. Rochas and I. Burgert, *Biomacromolecules*, 2012, **13**, 850–856.

2953 259 R. Kumar, R. Kr. Sharma and A. P. Singh, *Journal of Molecular Liquids*, 2017, **232**, 62–93.

2954 260 W. G. Glasser, in *Glycoscience*, eds. B. O. Fraser-Reid, K. Tatsuta and J. Thiem, Springer Berlin Heidelberg, Berlin, Heidelberg, 2008, pp. 1473–1512.

2956 261 A. Etale, A. J. Onyianta, S. R. Turner and S. J. Eichhorn, *Chem. Rev.*, 2023, **123**, 2016–2048.

2957 262 M. Wohlert, T. Benselfelt, L. Wågberg, I. Furó, L. A. Berglund and J. Wohlert, *Cellulose*, 2022, **29**, 1–23.

2959 263 M. Börjesson and G. Westman, in *Cellulose - Fundamental Aspects and Current Trends*, eds. M. Poletto and H. L. Ornaghi, InTech, 2015.

2961 264 P. A. R. Pires, N. I. Malek, T. C. Teixeira, T. A. Bioni, H. Nawaz and O. A. E. Seoud, *Industrial Crops and Products*, 2015, **77**, 180–189.

2963 265 T. Ishida, *J. Phys. Chem. B*, 2020, **124**, 3090–3102.

2964 266 T. Shen and S. Gnanakaran, *Biophysical Journal*, 2009, **96**, 3032–3040.

2965 267 V. Barbash and O. Yaschenko, in *Novel Nanomaterials*, ed. K. Krishnamoorthy, IntechOpen, 2021.
2966

2967

268 M. Jakob, A. R. Mahendran, W. Gindl-Altmutter, P. Bliem, J. Konnerth, U. Müller and S. Veigel, *Progress in Materials Science*, 2022, **125**, 100916.

2968

269 R. J. Moon, A. Martini, J. Nairn, J. Simonsen and J. Youngblood, *Chem. Soc. Rev.*, 2011, **40**, 3941.

2969

270 P. Tayeb and A. H. Tayeb, *Carbohydrate Polymers*, 2019, **224**, 115149.

2970

271 K. Zhang, A. Barhoum, C. Xiaoqing, H. Li and P. Samyn, in *Handbook of Nanofibers*, eds. A. Barhoum, M. Bechelany and A. S. H. Makhlouf, Springer International Publishing, Cham, 2019, pp. 409–449.

2972

272 D. Klemm, B. Heublein, H. Fink and A. Bohn, *Angew Chem Int Ed.*, 2005, **44**, 3358–3393.

2974

273 A. N. Vu, L. H. Nguyen, H.-C. V. Tran, K. Yoshimura, T. D. Tran, H. Van Le and N.-U. T. Nguyen, *RSC Adv.*, 2024, **14**, 2048–2060.

2976

274 T. W. Kurniawan, H. Sulistyarti, B. Rumhayati and A. Sabarudin, *Journal of Chemistry*, 2023, **2023**, 1–36.

2978

275 P. Samyn, A. Meftahi, S. A. Geravand, M. E. M. Heravi, H. Najarzadeh, M. S. K. Sabery and A. Barhoum, *International Journal of Biological Macromolecules*, 2023, **231**, 123316.

2980

276 I. D. A. A. Fernandes, G. M. Maciel, I. S. Ribeiro, A. C. Pedro, D. G. Bortolini, V. R. Ribeiro, L. Barros and C. W. I. Haminiuk, *International Journal of Biological Macromolecules*, 2023, **240**, 124349.

2982

277 B. Niknafs, M. Meskaraf-asadabadi, K. Hamdi and E. Ghanbari, *International Journal of Biological Macromolecules*, 2024, **266**, 131167.

2984

278 A. Babaei-Ghazvini, B. Vafakish, R. Patel, K. J. Falua, M. J. Dunlop and B. Acharya, *International Journal of Biological Macromolecules*, 2024, **258**, 128834.

2986

279 M. Pääkkö, M. Ankerfors, H. Kosonen, A. Nykänen, S. Ahola, M. Österberg, J. Ruokolainen, J. Laine, P. T. Larsson, O. Ikkala and T. Lindström, *Biomacromolecules*, 2007, **8**, 1934–1941.

2988

280 N. Lavoine, I. Desloges, A. Dufresne and J. Bras, *Carbohydrate Polymers*, 2012, **90**, 735–764.

2989

281 N. Ninan, M. Muthiah, I.-K. Park, A. Elain, S. Thomas and Y. Grohens, *Carbohydrate Polymers*, 2013, **98**, 877–885.

2991

282 A. Kumar, T. Jyske and M. Petrič, *Advanced Sustainable Systems*, 2021, **5**, 2000251.

2992

283 F. Barthelat, Z. Yin and M. J. Buehler, *Nat Rev Mater*, 2016, **1**, 16007.

2993

284 C. Chen, Y. Kuang, S. Zhu, I. Burgert, T. Keplinger, A. Gong, T. Li, L. Berglund, S. J. Eichhorn and L. Hu, *Nat Rev Mater*, 2020, **5**, 642–666.

2995

285 L. H. Thomas, V. T. Forsyth, A. Martel, I. Grillo, C. M. Altaner and M. C. Jarvis, *Cellulose*, 2014, **21**, 3887–3895.

2997

286 J. Zheng, Y. Li, H. Morris, F. Vandelook and S. Jansen, *Front. Plant Sci.*, 2022, **13**, 774241.

2998

287 L. A. Donaldson, M. Cairns and S. J. Hill, *Plant Physiol.*, 2018, **178**, 1142–1153.

2999

288 M. H. Ramage, H. Burridge, M. Busse-Wicher, G. Fereday, T. Reynolds, D. U. Shah, G. Wu, L. Yu, P. Fleming, D. Densley-Tingley, J. Allwood, P. Dupree, P. F. Linden and O. Scherman, *Renewable and Sustainable Energy Reviews*, 2017, **68**, 333–359.

3000

3001

289 S. Fang and Y. H. Hu, *Chem. Commun.*, 2024, **60**, 7663–7671.

3002

290 V. P. Kalpana and V. T. Perarasu, *Journal of Molecular Structure*, 2020, **1217**, 128350.

3004

291 B. Chieng, S. Lee, N. Ibrahim, Y. Then and Y. Loo, *Polymers*, 2017, **9**, 355.

3005

292 D. Trache, A. F. Tarchoun, M. Derradji, T. S. Hamidon, N. Masruchin, N. Brosse and M. H. Hussin, *Front. Chem.*, 2020, **8**, 392.

3006

293 P. Phanthong, P. Reubroycharoen, X. Hao, G. Xu, A. Abudula and G. Guan, *Carbon Resources Conversion*, 2018, **1**, 32–43.

3008
3009 294 N. T. U. Culsum, A. Wibowo, Subagjo and Y. W. Budhi, *Biocatalysis and Agricultural Biotechnology*, 2023, **54**, 102915.

3011 295 D. Abol-Fotouh, M. A. Hassan, H. Shokry, A. Roig, M. S. Azab and A. E.-H. B. Kashyout, *Sci Rep*, 2020, **10**, 3491.

3013 296 I. Algar, S. C. M. Fernandes, G. Mondragon, C. Castro, C. Garcia-Astrain, N. Gabilondo, A. Retegi and A. Eceiza, *J of Applied Polymer Sci*, 2015, **132**, app.41237.

3015 297 L. Solhi, V. Guccini, K. Heise, I. Solala, E. Niinivaara, W. Xu, K. Mihhels, M. Kröger, Z. Meng, J. Wohlert, H. Tao, E. D. Cranston and E. Kontturi, *Chem. Rev.*, 2023, **123**, 1925–2015.

3017 298 D. Tahir, M. R. A. Karim, H. Hu, S. Naseem, M. Rehan, M. Ahmad and M. Zhang, *Polymers*, 2022, **14**, 4468.

3019 299 T. G. M. Van De Ven and A. Sheikhi, *Nanoscale*, 2016, **8**, 15101–15114.

3020 300 C. Campano, P. Lopez-Exposito, A. Blanco, C. Negro and T. G. M. Van De Ven, *Cellulose*, 2019, **26**, 6275–6289.

3022 301 M. Faisal, M. Žmirić, N. Kim, S. Bruun, L. Mariniello, M. Famiglietti, H. Bordallo, J. Kirkensgaard, B. Jørgensen, P. Ulvskov, K. Hebelstrup and A. Blennow, *Coatings*, 2023, **13**, 1573.

3024 302 M. S. Islam, L. Chen, J. Sisler and K. C. Tam, *J. Mater. Chem. B*, 2018, **6**, 864–883.

3025 303 C. Salas, T. Nypelö, C. Rodriguez-Abreu, C. Carrillo and O. J. Rojas, *Current Opinion in Colloid & Interface Science*, 2014, **19**, 383–396.

3027 304 C. Sharma and N. K. Bhardwaj, *Materials Science and Engineering: C*, 2019, **104**, 109963.

3028 305 S. Mishra, P. K. Singh, R. Pattnaik, S. Kumar, S. K. Ojha, H. Srichandan, P. K. Parhi, R. K. Jyothi and P. K. Sarangi, *Front. Bioeng. Biotechnol.*, 2022, **10**, 780409.

3030 306 D. Lahiri, M. Nag, B. Dutta, A. Dey, T. Sarkar, S. Pati, H. A. Edinur, Z. Abdul Kari, N. H. Mohd Noor and R. R. Ray, *IJMS*, 2021, **22**, 12984.

3032 307 A. Krystynowicz, W. Czaja, A. Wiktorowska-Jezierska, M. Gončalves-Mi?kiewicz, M. Turkiewicz and S. Bielecki, *Journal of Industrial Microbiology and Biotechnology*, 2002, **29**, 189–195.

3034 308 Z. Shi, Y. Zhang, G. O. Phillips and G. Yang, *Food Hydrocolloids*, 2014, **35**, 539–545.

3035 309 M. Moniri, A. Boroumand Moghaddam, S. Azizi, R. Abdul Rahim, A. Bin Ariff, W. Zuhainis Saad, M. Navaderi and R. Mohamad, *Nanomaterials*, 2017, **7**, 257.

3037 310 J. K. Muiruri, J. C. C. Yeo, Q. Zhu, E. Ye, X. J. Loh and Z. Li, *European Polymer Journal*, 2023, **199**, 112446.

3039 311 D. A. Gregory, L. Tripathi, A. T. R. Fricker, E. Asare, I. Orlando, V. Raghavendran and I. Roy, *Materials Science and Engineering: R: Reports*, 2021, **145**, 100623.

3041 312 A. M. Dube, B. J. Daba and M. D. Muleta, *Journal of Experimental Nanoscience*, 2023, **18**, 2199989.

3043 313 E. Galiwango, N. S. Abdel Rahman, A. H. Al-Marzouqi, M. M. Abu-Omar and A. A. Khaleel, *Heliyon*, 2019, **5**, e02937.

3045 314 J. Mao, H. Abushammala, H. Hettegger, T. Rosenau and M.-P. Laborie, *Polymers*, 2017, **9**, 473.

3046 315 Q. He, Y. Bai, Y. Lu, B. Cui, Z. Huang, Q. Yang, D. Jiang and D. Shao, *Biomass Conv. Bioref.*, , DOI:10.1007/s13399-022-03380-6.

3048 316 H. Koga, K. Nagashima, Y. Huang, G. Zhang, C. Wang, T. Takahashi, A. Inoue, H. Yan, M. Kanai, Y. He, K. Uetani, M. Nogi and T. Yanagida, *ACS Appl. Mater. Interfaces*, 2019, **11**, 15044–15050.

3050 317 N. Forsman, A. Lozhechnikova, A. Khakalo, L.-S. Johansson, J. Vartiainen and M. Österberg, *Carbohydrate Polymers*, 2017, **173**, 392–402.
3052 318 M. P. Arrieta, E. Fortunati, N. Burgos, M. A. Peltzer, J. López and L. Peponi, in *Multifunctional Polymeric Nanocomposites Based on Cellulosic Reinforcements*, Elsevier, 2016, pp. 205–252.

3053 319 A. K. Tamo, T. A. Tran, I. Doench, S. Jahangir, A. Lall, L. David, C. Peniche-Covas, A. Walther and A. Osorio-Madrazo, *Materials*, 2022, **15**, 6039.

3054 320 D. Srivastava, M. S. Kuklin, J. Ahopelto and A. J. Karttunen, *Carbohydrate Polymers*, 2020, **243**, 116440.

3055 321 S. Jackson and J. Chen, *AATCC Journal of Research*, 2024, **11**, 151–170.

3056 322 Y. El-Ghoul, A. S. Altuwayjiri and G. A. Alharbi, *RSC Adv.*, 2024, **14**, 26183–26197.

3057 323 M. Raza, J. Mustafa, A. H. Al-Marzouqi and B. Abu-Jdayil, *International Journal of Thermofluids*, 2024, **21**, 100548.

3058 324 C. Trilokesh and K. B. Uppuluri, *Sci Rep*, 2019, **9**, 16709.

3059 325 V. U. Siddiqui, T. M. Almehjani, S. M. Sapuan, T. Jamal, R. A. Ilyas, S. M. Eldin, A. Khan and Y. Jameel, *Journal of Natural Fibers*, 2024, **21**, 2299943.

3060 326 A. S. Hozman-Manrique, A. J. Garcia-Brand, M. Hernández-Carrión and A. Porras, *Polymers*, 2023, **15**, 664.

3061 327 M. Raza, B. Abu-Jdayil, F. Banat and A. H. Al-Marzouqi, *ACS Omega*, 2022, **7**, 25366–25379.

3062 328 T. Agarwal, S. N. G. H. Narayana, K. Pal, K. Pramanik, S. Giri and I. Banerjee, *International Journal of Biological Macromolecules*, 2015, **75**, 409–417.

3063 329 I. Doench, M. Torres-Ramos, A. Montembault, P. Nunes De Oliveira, C. Halimi, E. Viguier, L. Heux, R. Siadous, R. Thiré and A. Osorio-Madrazo, *Polymers*, 2018, **10**, 1202.

3064 330 K. Hou, Y. Li, Y. Liu, R. Zhang, B. S. Hsiao and M. Zhu, *Polymer*, 2017, **123**, 55–64.

3065 331 M. A. Hubbe, P. Tayeb, M. Joyce, P. Tyagi, M. Kehoe, K. Dimic-Misic and L. Pal, *BioRes*, 2017, **12**, 9556–9661.

3066 332 D. Srivastava, J. Ahopelto and A. J. Karttunen, *Molecules*, 2022, **27**, 6240.

3067 333 A. D. French, in *Encyclopedia of Biophysics*, ed. G. C. K. Roberts, Springer Berlin Heidelberg, Berlin, Heidelberg, 2013, pp. 248–253.

3068 334 D. K. Patel, S. D. Dutta and K.-T. Lim, *RSC Adv.*, 2019, **9**, 19143–19162.

3069 335 E. M. Debzi, H. Chanzy, J. Sugiyama, P. Tekely and G. Excoffier, *Macromolecules*, 1991, **24**, 6816–6822.

3070 336 J. F. Matthews, M. E. Himmel and M. F. Crowley, *Cellulose*, 2012, **19**, 297–306.

3071 337 J. A. Sirviö and M. Lakovaara, *Biomacromolecules*, 2021, **22**, 3366–3376.

3072 338 Q. Wu, J. Xu, S. Zhu, Y. Kuang, B. Wang and W. Gao, *Carbohydrate Polymers*, 2020, **249**, 116827.

3073 339 M. Wada, H. Chanzy, Y. Nishiyama and P. Langan, *Macromolecules*, 2004, **37**, 8548–8555.

3074 340 P. H. Hermans and A. Weidinger, *Journal of Colloid Science*, 1946, **1**, 495–504.

3075 341 A. Okiyama, M. Motoki and S. Yamanaka, *Food Hydrocolloids*, 1993, **6**, 503–511.

3076 342 R. N. Goldberg, J. Schliesser, A. Mittal, S. R. Decker, A. F. L. O. M. Santos, V. L. S. Freitas, A. Urbas, B. E. Lang, C. Heiss, M. D. M. C. Ribeiro Da Silva, B. F. Woodfield, R. Katahira, W. Wang and D. K. Johnson, *The Journal of Chemical Thermodynamics*, 2015, **81**, 184–226.

3077 343 Y. Nishiyama, J. Sugiyama, H. Chanzy and P. Langan, *J. Am. Chem. Soc.*, 2003, **125**, 14300–14306.

3078 344 S. Park, R. A. Venditti, D. G. Abrecht, H. Jameel, J. J. Pawlak and J. M. Lee, *J of Applied Polymer Sci*, 2007, **103**, 3833–3839.

3079 345 A. Kafy, H. C. Kim, L. Zhai, J. W. Kim, L. V. Hai, T. J. Kang and J. Kim, *Sci Rep*, 2017, **7**, 17683.
3095 346 Y. Wang, P. Zhang, J. Guo, Z. Zhong, W. Li and X. Liu, *BioRes*, 2023, **18**, 5813-5837.

3096 347 Y. Liu, B. Li, W. Mao, W. Hu, G. Chen, Y. Liu and Z. Fang, *ACS Omega*, 2019, **4**, 7861-7865.

3097 348 J. Wang, Q. Gao, Y. Wang, X. Liu and S. Nie, *Industrial Crops and Products*, 2022, **178**, 114599.

3098 349 M. R. K. Sofla, R. J. Brown, T. Tsuzuki and T. J. Rainey, *Adv. Nat. Sci: Nanosci. Nanotechnol.*, 2016, **7**, 035004.

3100 350 S. Eyley, C. Schütz and W. Thielemans, in *Cellulose Science and Technology*, eds. T. Rosenau, A. Potthast and J. Hell, *Wiley*, 2018, pp. 223-252.

3102 351 A. H. Nordin, S. Wong, N. Ngadi, M. Mohammad Zainol, N. A. F. Abd Latif and W. Nabgan, *Journal of Environmental Chemical Engineering*, 2021, **9**, 104639.

3104 352 J. M. Antoniw, V. A. Gabriel, M. V. Kiriakou, M. A. Dubé, M. F. Cunningham and E. D. Cranston, *RSC Appl. Polym.*, 2024, **2**, 262-274.

3106 353 S. Amine, A. Montembault, M. Fumagalli, A. Osorio-Madrazo and L. David, *Polymers*, 2021, **13**, 2023.

3108 354 A. Kondor, A. Santmarti, A. Mautner, D. Williams, A. Bismarck and K.-Y. Lee, *Front. Chem. Eng.*, 2021, **3**, 738995.

3110 355 A. Mautner, M. Hakalahti, V. Rissanen and T. Tammelin, in *Nanocellulose and Sustainability*, ed. K.-Y. Lee, CRC Press, Boca Raton: CRC Press, 2018 | Series: Sustainability contributions through science and technology, 1st edn., 2018, pp. 87-128.

3113 356 B. B. Hallac and A. J. Ragauskas, *Biofuels Bioprod Bioref*, 2011, **5**, 215-225.

3114 357 T. V. Patil, D. K. Patel, S. D. Dutta, K. Ganguly, T. S. Santra and K.-T. Lim, *Bioactive Materials*, 2022, **9**, 566-589.

3116 358 R. Alimohammadzadeh, A. A. Rafi, L. Goclik, C.-W. Tai and A. Cordova, *Carbohydrate Polymer Technologies and Applications*, 2022, **3**, 100205.

3118 359 Z. Yao, S. Mi, B. Chen, F. Liu, H. Na and J. Zhu, *ACS Sustainable Chem. Eng.*, 2022, **10**, 17327-17335.

3120 360 B. V. M. Rodrigues, R. T. Polez, O. A. El Seoud and E. Frollini, *International Journal of Biological Macromolecules*, 2023, **243**, 125256.

3122 361 B. P. Frank, D. P. Durkin, E. R. Caudill, L. Zhu, D. H. White, M. L. Curry, J. A. Pedersen and D. H. Fairbrother, *ACS Appl. Nano Mater.*, 2018, **1**, 7025-7038.

3124 362 G. Siqueira, J. Bras and A. Dufresne, *Langmuir*, 2010, **26**, 402-411.

3125 363 M. Lalanne-Tisné, S. Eyley, J. De Winter, A. Favrelle-Huret, W. Thielemans and P. Zinck, *Carbohydrate Polymers*, 2022, **295**, 119840.

3127 364 D. Roy, J. T. Guthrie and S. Perrier, *Macromolecules*, 2005, **38**, 10363-10372.

3128 365 Z. Zhang, X. Wang, K. C. Tam and G. Sèbe, *Carbohydrate Polymers*, 2019, **205**, 322-329.

3129 366 Z. Zhang, G. Sèbe, Y. Hou, J. Wang, J. Huang and G. Zhou, *J of Applied Polymer Sci*, 2021, **138**, 51458.

3131 367 M. Stepanova and E. Korzhikova-Vlakh, *Polymers*, 2022, **14**, 1477.

3132 368 G. Conzatti, S. Cavalie, C. Combes, J. Torrisani, N. Carrere and A. Tourrette, *Colloids and Surfaces B: Biointerfaces*, 2017, **151**, 143-155.

3134 369 D. Zhao, Y. Zhu, W. Cheng, W. Chen, Y. Wu and H. Yu, *Advanced Materials*, 2021, **33**, 2000619.

3135 370 K. Neubauerova, M. C. C. G. Carneiro, L. R. Rodrigues, F. T. C. Moreira and M. G. F. Sales, *Sensing and Bio-Sensing Research*, 2020, **29**, 100368.
3137 371 W. S. Thet Tun, A. Saenchoopa, S. Daduang, J. Daduang, S. Kulchat and R. Patramanon, RSC Adv., 2023, **13**, 9603–9614.

3139 372 J. Fan, M. Xu, Y.-T. Xu, W. Y. Hamad, Z. Meng and M. J. MacLachlan, *Chemical Engineering Journal*, 2023, **457**, 141175.

3141 373 Z. Deng, Z. Wu, M. Alizadeh, H. Zhang, Y. Chen and C. Karaman, *Environmental Research*, 2023, **219**, 114995.

3143 374 S. A. Al Kiey, A. M. Khalil and S. Kamel, *International Journal of Biological Macromolecules*, 2023, **239**, 124302.

3145 375 R. H. Althomali, K. A. Alamry, M. A. Hussein and R. M. Guedes, *Diamond and Related Materials*, 2022, **122**, 108803.

3147 376 J. Ji, L. Qu, Z. Wang, G. Li, W. Feng and G. Yang, *Microchemical Journal*, 2022, **175**, 107133.

3148 377 M. A. Khalilzadeh, S. Tajik, H. Beitollahi and R. A. Venditti, *Ind. Eng. Chem. Res.*, 2020, **59**, 4219–4228.

3150 378 H. N. Abdelhamid, D. Georgouvelas, U. Edlund and A. P. Mathew, *Chemical Engineering Journal*, 2022, **446**, 136614.

3152 379 V. Gautam, K. P. Singh and V. L. Yadav, *Carbohydrate Polymers*, 2018, **189**, 218–228.

3153 380 H.-A. S. Tohamy and H. S. Magar, *ECS J. Solid State Sci. Technol.*, 2022, **11**, 127003.

3154 381 Q. Bi, S. Dong, Y. Sun, X. Lu and L. Zhao, *Analytical Biochemistry*, 2016, **508**, 50–57.

3155 382 X. Wang, C. Karaman, Y. Zhang and C. Xia, *Chemosphere*, 2023, **331**, 138813.

3156 383 A. S. Santhosh, S. Sandeep, D. James Bound, S. Nandini, S. Nalini, G. S. Suresh, N. K. Swamy, J. R. Rajabathar and A. Selvaraj, *Surfaces and Interfaces*, 2021, **26**, 101377.

3158 384 E. Aparicio-Martínez, V. Osuna, R. B. Dominguez, A. Márquez-Lucero, E. A. Zaragoza-Contreras and A. Vega-Rios, *Journal of Nanomaterials*, 2018, **2018**, 1–9.

3160 385 V. Velusamy, S. Palanisamy, S.-W. Chen, S. Balu, T. C. K. Yang and C. E. Banks, *Talanta*, 2019, **192**, 471–477.

3162 386 Y. Zhang, G. Liu, X. Yao, S. Gao, J. Xie, H. Xu and N. Lin, *Cellulose*, 2018, **25**, 3861–3871.

3163 387 S. Ummartyotin and H. Manuspiya, *Renewable and Sustainable Energy Reviews*, 2015, **41**, 402–412.

3165 388 J. Moon, J.-A. Park, S.-J. Lee, T. Zyung and I.-D. Kim, *Sensors and Actuators B: Chemical*, 2010, **149**, 301–305.

3167 389 P. Sun, W. Wang, Y. Liu, Y. Sun, J. Ma and G. Lu, *Sensors and Actuators B: Chemical*, 2012, **173**, 52–57.

3169 390 M. Zhang, Z. Yuan, J. Song and C. Zheng, *Sensors and Actuators B: Chemical*, 2010, **148**, 87–92.

3170 391 L. Zhao, L. Zhao, Y. Xu, T. Qiu, L. Zhi and G. Shi, *Electrochimica Acta*, 2009, **55**, 491–497.

3171 392 Z. Pang, Z. Yang, Y. Chen, J. Zhang, Q. Wang, F. Huang and Q. Wei, *Colloids and Surfaces A: Physicochemical and Engineering Aspects*, 2016, **494**, 248–255.

3173 393 S. Yun and J. Kim, *Sensors and Actuators B: Chemical*, 2010, **150**, 308–313.

3174 394 J. Im, E. Sterner and T. Swager, *Sensors*, 2016, **16**, 183.

3175 395 M. L. Soriano and M. J. Dueñas-Mas, in *Carbon-Based Nanosensor Technology*, ed. C. Kranz, Springer International Publishing, Cham, 2018, vol. 17, pp. 273–301.

3177 396 H. Nawaz, W. Tian, J. Zhang, R. Jia, Z. Chen and J. Zhang, *ACS Appl. Mater. Interfaces*, 2018, **10**, 2114–2121.
3179 397 J. Yao, P. Ji, B. Wang, H. Wang and S. Chen, *Sensors and Actuators B: Chemical*, 2018, **254**, 110–119.

3181 398 K. B. R. Teodoro, F. L. Migliorini, W. A. Christinelli and D. S. Correa, *Carbohydrate Polymers*, 2019, **212**, 235–241.

3182 399 H. Orelma, A. Hokkanen, I. Leppänen, K. Kammiovirta, M. Kapulainen and A. Harlin, *Cellulose*, 2020, **27**, 1543–1553.

3183 400 S. Kumari and G. S. Chauhan, *ACS Appl. Mater. Interfaces*, 2014, **6**, 5908–5917.

3186 401 J. Fu, Z. Pang, J. Yang, F. Huang, Y. Cai and Q. Wei, *Applied Surface Science*, 2015, **349**, 35–42.

3187 402 B. W. Davis, N. Niamnont, C. D. Hare, M. Sukwattanasinitt and Q. Cheng, *ACS Appl. Mater. Interfaces*, 2010, **2**, 1798–1803.

3189 403 D. Chauhan and P. R. Solanki, *ACS Appl. Polym. Mater.*, 2019, **1**, 1613–1623.

3190 404 C. Esmaeili, M. Abdi, A. Mathew, M. Jonoobi, K. Oksman and M. Rezayi, *Sensors*, 2015, **15**, 24681–24697.

3192 405 H. Qi, E. Mäder and J. Liu, *Sensors and Actuators B: Chemical*, 2013, **185**, 225–230.

3193 406 X. Xu, J. Zhou, Y. Xin, G. Lubineau, Q. Ma and L. Jiang, *Sci Rep*, 2017, **7**, 4317.

3194 407 S. Veeralingam, P. Sahatiya, A. Kadu, V. Mattela and S. Badhulika, *ACS Appl. Electron. Mater.*, 2019, **1**, 558–568.

3196 408 E. Morales-Narváez, H. Golmohammadi, T. Naghdi, H. Yousefi, U. Kostiv, D. Horák, N. Pourreza and A. Merkoçi, *ACS Nano*, 2015, **9**, 7296–7305.

3198 409 N. Morimoto, F. M. Winnik and K. Akiyoshi, *Langmuir*, 2007, **23**, 217–223.

3199 410 C. Ruiz-Palomero, M. L. Soriano and M. Valcárcel, *Sensors and Actuators B: Chemical*, 2016, **229**, 31–37.

3201 411 M. Wang, I. V. Anoshkin, A. G. Nasibulin, J. T. Korhonen, J. Seitsonen, J. Pere, E. I. Kauppinen, R. H. A. Ras and O. Ikkala, *Advanced Materials*, 2013, **25**, 2428–2432.

3203 412 C. Ruiz-Palomero, M. L. Soriano and M. Valcárcel, *TrAC Trends in Analytical Chemistry*, 2017, **87**, 1–18.

3205 413 H. Wang, S. K. Biswas, S. Zhu, Y. Lu, Y. Yue, J. Han, X. Xu, Q. Wu and H. Xiao, *Nanomaterials*, 2020, **10**, 112.

3207 414 D. Kasprzak, I. Stępniak and M. Galiński, *J Solid State Electrochem*, 2018, **22**, 3035–3047.

3208 415 L. Li, F. Lu, C. Wang, F. Zhang, W. Liang, S. Kuga, Z. Dong, Y. Zhao, Y. Huang and M. Wu, *J. Mater. Chem. A*, 2018, **6**, 24468–24478.

3210 416 R. Liu, L. Ma, S. Huang, J. Mei, J. Xu and G. Yuan, *New J. Chem.*, 2017, **41**, 857–864.

3211 417 Z. Liu, J. Chen, Y. Zhan, B. Liu, C. Xiong, Q. Yang and G.-H. Hu, *ACS Sustainable Chem. Eng.*, 2019, **7**, 17653–17660.

3213 418 Z. Peng, Y. Zou, S. Xu, W. Zhong and W. Yang, *ACS Appl. Mater. Interfaces*, 2018, **10**, 22190–22200.

3215 419 M. G. Saborío, P. Svelic, J. Casanovas, G. Ruano, M. M. Pérez-Madrigal, L. Franco, J. Torras, F. Estrany and C. Alemán, *European Polymer Journal*, 2019, **118**, 347–357.

3217 420 P. Sun, W. He, H. Yang, R. Cao, J. Yin, C. Wang and X. Xu, *Nanoscale*, 2018, **10**, 19004–19013.

3218 421 H. Wang, E. Zhu, J. Yang, P. Zhou, D. Sun and W. Tang, *J. Phys. Chem. C*, 2012, **116**, 13013–13019.

3220 422 J. Xing, P. Tao, Z. Wu, C. Xing, X. Liao and S. Nie, *Carbohydrate Polymers*, 2019, **207**, 447–459.
3221 423 J. Berglund, D. Mikkelsen, B. M. Flanagan, S. Dhital, S. Gaunitz, G. Henriksson, M. E. Lindström, G. E. Yakubov, M. J. Gidley and F. Vilaplana, *Nat Commun*, 2020, **11**, 4692.

3222 424 L.-Z. Huang, M.-G. Ma, X.-X. Ji, S.-E. Choi and C. Si, *Front. Bioeng. Biotechnol.*, 2021, **9**, 690773.

3223 425 H. Østby and A. Várnai, *Essays in Biochemistry*, 2023, **67**, 533–550.

3224 426 N. Najjarzadeh, L. Matsakas, U. Rova and P. Christakopoulos, *Molecules*, 2020, **25**, 5849.

3225 427 N. Zhang, S. Li, L. Xiong, Y. Hong and Y. Chen, *Modelling Simul. Mater. Sci. Eng.*, 2015, **23**, 085010.

3226 428 N. M. L. Hansen and D. Plackett, *Biomacromolecules*, 2008, **9**, 1493–1505.

3227 429 H. V. Scheller and P. Ulvskov, *Annu. Rev. Plant Biol.*, 2010, **61**, 263–289.

3230 430 X. Zhou, W. Li, R. Mabon and L. J. Broadbelt, *Energy Environ. Sci.*, 2018, **11**, 1240–1260.

3231 431 X. Jin, Z. Hu, S. Wu, T. Song, F. Yue and Z. Xiang, *Carbohydrate Polymers*, 2019, **215**, 235–245.

3232 432 Y. Zheng, J. Shi, M. Tu and Y.-S. Cheng, in *Advances in Bioenergy*, Elsevier, 2017, vol. 2, pp. 1–68.

3233 433 W. Farhat, R. Venditti, A. Quick, M. Taha, N. Mignard, F. Becquart and A. Ayoub, *Industrial Crops and Products*, 2017, **107**, 370–377.

3234 434 A. Shukla, D. Kumar, M. Girdhar, A. Kumar, A. Goyal, T. Malik and A. Mohan, *Biotechnol Biofuels*, 2023, **16**, 44.

3235 435 S. G. C. De Almeida, V. T. F. Silva, J. P. De Souza, C. D. Prado, D. K. S. Oliveira, D. D. V. Silva and K. J. Dussán, in *Current Advances in Biotechnological Production of Xylitol*, eds. M. D. G. De Almeida Felipe and A. K. Chandel, Springer International Publishing, Cham, 2022, pp. 1–31.

3236 436 Y. Lu, Q. He, G. Fan, Q. Cheng and G. Song, *Green Processing and Synthesis*, 2021, **10**, 779–804.

3237 437 Z. Yan, M. A. Alam, J. Li, W. Xiong, S. Zhang, Z. Zhan and J. Xu, *Bioenerg. Res.*, 2024, **17**, 1469–1480.

3238 438 J. Rao, Z. Lv, G. Chen and F. Peng, *Progress in Polymer Science*, 2023, **140**, 101675.

3239 439 Y. Zeng, M. E. Himmel and S.-Y. Ding, *Biotechnol Biofuels*, 2017, **10**, 263.

3240 440 I. Gabrielii, P. Gatenholm, W. G. Glasser, R. K. Jain and L. Kenne, *Carbohydrate Polymers*, 2000, **43**, 367–374.

3241 441 C. Chen, W. Yin, G. Chen, G. Sun and G. Wang, *Materials*, 2017, **10**, 514.

3242 442 E. M. Jincy and K. S. Femina, in *Handbook of Biomass*, eds. S. Thomas, M. Hosur, D. Pasquini and C. Jose Chirayil, Springer Nature Singapore, Singapore, 2023, pp. 1–32.

3243 443 F. Delbecq, Y. Wang, A. Muralidhara, K. El Ouardi, G. Marlair and C. Len, *Front. Chem.*, 2018, **6**, 146.

3244 444 L.-P. Xiao, G.-Y. Song and R.-C. Sun, in *Hydrothermal Processing in Biorefineries*, eds. H. A. Ruiz, M. Hedegaard Thomsen and H. L. Trajano, Springer International Publishing, Cham, 2017, pp. 45–94.

3245 445 J. Puls, *Macromolecular Symposia*, 1997, **120**, 183–196.

3246 446 A. Ebringerová, *Macromolecular Symposia*, 2005, **232**, 1–12.

3247 447 K. Werner, L. Pommer and M. Broström, *Journal of Analytical and Applied Pyrolysis*, 2014, **110**, 130–137.

3248 448 H. A. Ruiz, M. A. Cerqueira, H. D. Silva, R. M. Rodríguez-Jasso, A. A. Vicente and J. A. Teixeira, *Carbohydrate Polymers*, 2013, **92**, 2154–2162.

3249 449 W. Duan, A. González, M. Gich and C. Fernández-Sánchez, *ACS Sustainable Chem. Eng.*, 2024, **12**, 4386–4397.
3263

3264

450 W. Zhang, J.-Y. Wen, M.-G. Ma, M.-F. Li, F. Peng and J. Bian, *Journal of Materials Research and Technology*, 2021, **14**, 555-566.

3265

451 Y. Li, M. Yao, Y. Luo, J. Li, Z. Wang, C. Liang, C. Qin, C. Huang and S. Yao, *ACS Appl. Mater. Interfaces*, 2023, **15**, 5883-5896.

3266

3267

452 X. Gong, C. Fu, N. Alam, Y. Ni, L. Chen, L. Huang and H. Hu, *Biomacromolecules*, 2022, **23**, 2272-2279.

3268

3269

453 Y. Xu, K. Liu, Y. Yang, M.-S. Kim, C.-H. Lee, R. Zhang, T. Xu, S.-E. Choi and C. Si, *Front. Bioeng. Biotechnol.*, 2023, **10**, 1110004.

3270

3271

454 R. Chen, H. Tang, Y. Dai, W. Zong, W. Zhang, G. He and X. Wang, *ACS Nano*, 2022, **16**, 19124-19132.

3272

3273

455 W. Zhang, J. Wen, J. Yang, M. Li, F. Peng, M. Ma and J. Bian, *International Journal of Biological Macromolecules*, 2022, **223**, 1-10.

3274

3275

456 K. Sharma, M. Kaur, P. Tewatia, V. Kumar, C. Paulik, H. Yoshitake, M. Sharma, G. Rattan, S. Singhal and A. Kaushik, *Bioresource Technology*, 2023, **389**, 129825.

3276

3277

457 R. Farma, I. Apriyani, A. Awitdrus, E. Taer and A. Apriwandi, *Sci Rep*, 2022, **12**, 2572.

3278

458 L. Hu, Y. Xie, S. Gao, X. Shi, C. Lai, D. Zhang, C. Lu, Y. Liu, L. Du, X. Fang, F. Xu, C. Wang and F. Chu, *Carbohydrate Polymers*, 2023, **312**, 120827.

3279

3280

459 R. Helim, A. Zazoua, N. Jaffrezic-Renault and H. Korri-Youssoufi, *Talanta*, 2023, **265**, 124784.

3281

460 C. Falco, J. M. Sieben, N. Brun, M. Sevilla, T. van der Mauelen, E. Morallón, D. Cazorla-Amorós and M. Titirici, *ChemSusChem*, 2013, **6**, 374-382.

3282

3283

461 H. Lin, Y. Liu, Z. Chang, S. Yan, S. Liu and S. Han, *Microporous and Mesoporous Materials*, 2020, **292**, 109707.

3284

3285

462 X. Jiang, J. Huang, T. Chen, Q. Zhao, F. Xu and X. Zhang, *International Journal of Biological Macromolecules*, 2020, **153**, 412-420.

3286

3287

463 P. Yang, Z. Zhu, M. Chen, W. Chen and X. Zhou, *Optical Materials*, 2018, **85**, 329-336.

3288

464 P. Yang, Z. Zhu, M. Chen, X. Zhou and W. Chen, *Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy*, 2019, **213**, 301-308.

3289

3290

465 A. Dammak, C. Moreau, N. Beury, K. Schwikal, H. T. Winter, E. Bonnin, B. Saake and B. Cathala, *Holzforschung*, 2013, **67**, 579-586.

3291

3292

466 L. Hu, S. Gao, L. Zhao, L. Dai, D. Zhang, C. Wang, X. Fang and F. Chu, *Gels*, 2023, **9**, 725.

3293

467 P. T. Martone, J. M. Estevez, F. Lu, K. Ruel, M. W. Denny, C. Somerville and J. Ralph, *Current Biology*, 2009, **19**, 169-175.

3294

3295

468 Z. Mahmood, M. Yameen, M. Jahangeer, M. Riaz, A. Ghaffar and I. Javid, in *Lignin - Trends and Applications*, ed. M. Poletto, InTech, 2018.

3296

3297

469 Q. Liu, L. Luo and L. Zheng, *IJMS*, 2018, **19**, 335.

3298

470 Y. Lu, Y.-C. Lu, H.-Q. Hu, F.-J. Xie, X.-Y. Wei and X. Fan, *Journal of Spectroscopy*, 2017, **2017**, 1-15.

3299

3300

471 E. M. Anderson, M. L. Stone, R. Katahira, M. Reed, W. Muchero, K. J. Ramirez, G. T. Beckham and Y. Román-Leshkov, *Nat Commun.*, 2019, **10**, 2033.

3301

3302

472 Z. Wang, S. Qiu, K. Hirth, J. Cheng, J. Wen, N. Li, Y. Fang, X. Pan and J. Y. Zhu, *ACS Sustainable Chem. Eng.*, 2019, **7**, 10808-10820.

3303

3304

473 D. Watkins, Md. Nuruddin, M. Hosur, A. Tcherbi-Narteh and S. Jeelani, *Journal of Materials Research and Technology*, 2015, **4**, 26-32.

3305
3306 474 S. Dhara, N. S. Samanta, R. Uppaluri and M. K. Purkait, *International Journal of Biological Macromolecules*, 2023, **234**, 123594.

3307 475 T. A. Shah, S. Khalid, H.-A. Nafidi, A. M. Salamatullah and M. Bourhia, *Sustainability*, 2023, **15**, 8755.

3310 476 M. Parot, D. Rodrigue and T. Stevanovic, *Bioresource Technology Reports*, 2022, **17**, 100880.

3311 477 D. S. Zijlstra, C. W. Lahive, C. A. Analbers, M. B. Figueirêdo, Z. Wang, C. S. Lancefield and P. J. Deuss, *ACS Sustainable Chem. Eng.*, 2020, **8**, 5119-5131.

3313 478 E. Liu, M. I. V. Mercado, F. Segato and M. R. Wilkins, *Enzyme and Microbial Technology*, 2024, **174**, 110392.

3315 479 E. C. Achinivu, R. M. Howard, G. Li, H. Gracz and W. A. Henderson, *Green Chem.*, 2014, **16**, 1114-1119.

3317 480 E. O. Owhe, N. Kumar and J. G. Lynam, *Biocatalysis and Agricultural Biotechnology*, 2021, **32**, 101949.

3319 481 J. Li, G. Gellerstedt and K. Toven, *Bioresource Technology*, 2009, **100**, 2556-2561.

3320 482 S. Angelini, D. Ingles, M. Gelosia, P. Cerruti, E. Pompili, G. Scarinzi, G. Cavalaglio, F. Cotana and M. Malinconico, *Journal of Cleaner Production*, 2017, **151**, 152-162.

3322 483 X. Zhang, J. Zhu, L. Sun, Q. Yuan, G. Cheng and D. S. Argyropoulos, *Industrial Crops and Products*, 2019, **133**, 241-249.

3324 484 F. Nardella, J. Prothmann, M. Sandahl, P. Spégel, E. Ribechini and C. Turner, *RSC Adv.*, 2023, **13**, 21945-21953.

3326 485 J. Ho Seo, H. Jeong, H. W. Lee, C. S. Choi, J. H. Bae, S. M. Lee and Y. S. Kim, *Bioresource Technology*, 2019, **275**, 368-374.

3328 486 S. Zhang, Z. Dong, J. Shi, C. Yang, Y. Fang, G. Chen, H. Chen and C. Tian, *Bioresource Technology*, 2022, **361**, 127699.

3330 487 C. Chang and P. Gupta, *Biomacromolecules*, 2023, **24**, 1220-1232.

3331 488 E. García-Cisneros, F. S. Mederos-Nieto, R. Hernández-Altamirano, M. A. González-Espinosa and V. Castillejos-Torres, *Biofuels*, 2024, **15**, 793-800.

3333 489 N. Muhammad, Z. Man, M. A. Bustam, M. I. A. Mutalib and S. Rafiq, *Journal of Industrial and Engineering Chemistry*, 2013, **19**, 207-214.

3335 490 A. Meraj, M. Jawaid, S. P. Singh, M. M. Nasef, H. Ariffin, H. Fouad and B. Abu-Jdayil, *Sci Rep*, 2024, **14**, 8672.

3337 491 T. Rashid, N. Gnanasundaram, A. Appusamy, C. F. Kait and M. Thanabalan, *Industrial Crops and Products*, 2018, **116**, 122-136.

3339 492 D. Gnana Prakash, K. P. Gopinath, S. M. Prasanth, S. Harish, M. Rishikesh, R. Sivaramakrishnan and A. Pugazhendhi, *Chemosphere*, 2022, **293**, 133473.

3341 493 R. Y. Nsimba, C. A. Mullen, N. M. West and A. A. Boateng, *ACS Sustainable Chem. Eng.*, 2013, **1**, 260-267.

3343 494 V. Provost, S. Dumarcay, I. Ziegler-Devin, M. Boltoeva, D. Trébouet and M. Villain-Gambier, *Bioresource Technology*, 2022, **349**, 126837.

3345 495 H. Luo and M. M. Abu-Omar, *Green Chem.*, 2018, **20**, 745-753.

3346 496 J. Zheng, L. Chen, Z. Huang and X. Qiu, *Green Chem.*, 2024, **26**, 2783-2792.

3347 497 C. Xu and F. Ferdosian, *Conversion of Lignin into Bio-Based Chemicals and Materials*, Springer Berlin Heidelberg, Berlin, Heidelberg, 2017.
3349 498 M. S. Ganewatta, H. N. Lokupitiya and C. Tang, *Polymers*, 2019, **11**, 1176.

3350 499 C. Welker, V. Balasubramanian, C. Petti, K. Rai, S. DeBolt and V. Mendu, *Energies*, 2015, **8**, 7654–7676.

3351 500 D. Tarasov, M. Leitch and P. Fatehi, *Biotechnol Biofuels*, 2018, **11**, 269.

3352 501 A. Tolbert, H. Akinosho, R. Khunsupat, A. K. Naskar and A. J. Ragauskas, *Biofuels Bioprod Bioref*, 2014, **8**, 836–856.

3353 502 S. Sugiarto, Y. Leow, C. L. Tan, G. Wang and D. Kai, *Bioactive Materials*, 2022, **8**, 71–94.

3354 503 D. Wang, Y. Gu, S. Feng, W. Yang, H. Dai, H. Xiao and J. Han, *Green Chem.*, 2023, **25**, 9020–9044.

3355 504 S. Sen, S. Patil and D. S. Argyropoulos, *Green Chem.*, 2015, **17**, 4862–4887.

3356 505 S. Laurichesse and L. Avérous, *Progress in Polymer Science*, 2014, **39**, 1266–1290.

3357 506 B. Yu, Z. Chang and C. Wang, *Materials Chemistry and Physics*, 2016, **181**, 187–193.

3360 507 I. Spiridon, *Environ Chem Lett*, 2020, **18**, 771–785.

3361 508 J. Y. Ryu and E. J. Na, *biomed dermatol*, 2018, **2**, 15.

3362 509 A. P. Richter, J. S. Brown, B. Bharti, A. Wang, S. Gangwal, K. Houck, E. A. Cohen Hubal, V. N. Paunov, S. D. Stoyanov and O. D. Velev, *Nature Nanotech*, 2015, **10**, 817–823.

3363 510 M. Özparpucu, N. Gierlinger, I. Cesarino, I. Burgert, W. Boerjan and M. Rüggeberg, *Journal of Experimental Botany*, 2019, **70**, 4039–4047.

3364 511 W. J. Cousins, *Wood Sci. Technol.*, 1976, **10**, 9–17.

3365 512 A. Emonet and A. Hay, *Plant Physiology*, 2022, **190**, 31–43.

3366 513 M. Schwaighofer, L. Zelaya-Lainez, M. Königsberger, M. Lukacevic, S. Serna-Loaiza, M. Harasek, O. Lahayne, V. Senk and J. Füssl, *Materials & Design*, 2023, **227**, 111765.

3367 514 S. Sahoo, M. Misra and A. K. Mohanty, *Composites Part A: Applied Science and Manufacturing*, 2011, **42**, 1710–1718.

3368 515 A. Shakoor Shar, N. Wang, T. Chen, X. Zhao and Y. Weng, *Polymers*, 2023, **15**, 4049.

3369 516 D. Zappi, G. Varani, E. Cozzoni, I. Iatsunskyi, S. Laschi and M. T. Giardi, *Nanomaterials*, 2021, **11**, 3428.

3370 517 J. S. Rodrigues, A. De S. M. De Freitas, L. F. De Lima, H. S. M. Lopes, C. C. Maciel, L. V. B. V. Fré, A. A. F. Pires, V. H. De Lima, V. J. R. Oliveira, C. De A. Olivati, M. Ferreira, A. Riul and V. R. Botaro, *International Journal of Biological Macromolecules*, 2024, **268**, 131883.

3371 518 A. Antonacci, V. Frisulli, L. B. Carvalho, L. F. Fraceto, B. Miranda, L. De Stefano, U. Johanningmeier, M. T. Giardi and V. Scognamiglio, *IJMS*, 2023, **24**, 10088.

3372 519 M. Vasudevan, S. Remesh, V. Perumal, P. B. Raja, M. N. M. Ibrahim, S. C. B. Gopinath, H.-L. Lee, S. Karuppanan, M. Ovinis, N. Arumugam and R. S. Kumar, *Microchemical Journal*, 2023, **195**, 109405.

3373 520 C. Tortolini, E. Capecchi, F. Tasca, R. Pofi, M. A. Venneri, R. Saladino and R. Antiochia, *Nanomaterials*, 2021, **11**, 718.

3374 521 L. Cui, H. Xu, Y. An, M. Xu, Z. Lei and X. Jin, *Advanced Powder Technology*, 2022, **33**, 103571.

3375 522 H. Liu, Y. Guan, L. Yan, Y. Zheng, C. Si and L. Dai, *Green Chem.*, 2024, **26**, 9281–9294.

3376 523 S. Paul, N. S. Thakur, S. Chandna, V. Sagar and J. Bhaumik, *ACS Appl. Nano Mater.*, 2022, **5**, 2748–2761.

3377 524 Y. Lei, A. H. Alshareef, W. Zhao and S. Inal, *ACS Appl. Nano Mater.*, 2020, **3**, 1166–1174.

3378 525 S. Wang, M. T. Innocent, Q. Wang, H. Xiang, J. Tang and M. Zhu, *International Journal of Biological Macromolecules*, 2020, **151**, 730–739.
3392 526 F. A. Faria, D. V. Evtuguin, A. Rudnitskaya, M. T. Gomes, J. A. Oliveira, M. P. F. Graça and L. C. Costa, *Polym. Int.*, 2012, **61**, 788–794.

3394 527 M. Vasudevan, S. Remesh, V. Perumal, P. B. Raja, M. N. M. Ibrahim, S. C. B. Gopinath, S. Karuppanan and M. Ovinis, *Chemical Engineering Journal*, 2023, **468**, 143613.

3396 528 Z.-R. Hu, D.-D. Li, T.-H. Kim, M.-S. Kim, T. Xu, M.-G. Ma, S.-E. Choi and C. Si, *Front. Chem.*, 2022, **10**, 841956.

3398 529 T. Bao, Q. Wang, Y. Jiang, X. Zhao, Y. Cao, J. Cao, Q. Li and W. Si, *Crystals*, 2024, **14**, 506.

3399 530 S. S. L. Gonçalves, A. Rudnitskaya, A. J. M. Sales, L. M. C. Costa and D. V. Evtuguin, *Materials*, 2020, **13**, 1637.

3401 531 A. Duval and M. Lawoko, *Reactive and Functional Polymers*, 2014, **85**, 78–96.

3402 532 R. Chokkareddy, G. G. Redhi and T. Karthick, *Heliyon*, 2019, **5**, e01457.

3403 533 D. V. Stergiou, P. G. Veltsistas and M. I. Prodromidis, *Sensors and Actuators B: Chemical*, 2008, **129**, 903–908.

3405 534 L. Xu, W. Mao, J. Huang, S. Li, K. Huang, M. Li, J. Xia and Q. Chen, *Sensors and Actuators B: Chemical*, 2016, **230**, 54–60.

3407 535 S. Rai, B. K. Singh, P. Bhartiya, A. Singh, H. Kumar, P. K. Dutta and G. K. Mehrotra, *Journal of Luminescence*, 2017, **190**, 492–503.

3409 536 M. M. Pillai, K. R. Karpagam, R. Begam, R. Selvakumar and A. Bhattacharyya, *Materials Letters*, 2018, **212**, 78–81.

3411 537 A. Jędrzak, T. Rębiś, Ł. Klapiszewski, J. Zdarta, G. Milczarek and T. Jesionowski, *Sensors and Actuators B: Chemical*, 2018, **256**, 176–185.

3413 538 N. A. Nguyen, K. M. Meek, C. C. Bowland, S. H. Barnes and A. K. Naskar, *Macromolecules*, 2018, **51**, 115–127.

3415 539 Y. Xue, X. Qiu, Z. Liu and Y. Li, *ACS Sustainable Chem. Eng.*, 2018, **6**, 7695–7703.

3416 540 C. Chen, X. Wang, M. Li, Y. Fan and R. Sun, *Sensors and Actuators B: Chemical*, 2018, **255**, 1569–1576.

3418 541 V. Gigli, E. Capecchi, C. Tortolini, A. Isidori, R. Antiochia and R. Saladino, *ACS Biomater. Sci. Eng.*, 2023, **9**, 3597–3605.

3420 542 L. Meng, S. Chirtes, X. Liu, M. Eriksson and W. C. Mak, *Biosensors and Bioelectronics*, 2022, **218**, 114742.

3422 543 J. H. Park, H. H. Rana, J. Y. Lee and H. S. Park, *J. Mater. Chem. A*, 2019, **7**, 16962–16968.

3423 544 C. Xiong, W. Zhong, Y. Zou, J. Luo and W. Yang, *Electrochimica Acta*, 2016, **211**, 941–949.

3424 545 F. Li, X. Wang and R. Sun, *J. Mater. Chem. A*, 2017, **5**, 20643–20650.

3425 546 W. Chen, X. Wang, M. Feizbakhshan, C. Liu, S. Hong, P. Yang and X. Zhou, *Journal of Colloid and Interface Science*, 2019, **540**, 524–534.

3427 547 S. Hu, S. Zhang, N. Pan and Y.-L. Hsieh, *Journal of Power Sources*, 2014, **270**, 106–112.

3428 548 C. Ma, Z. Li, J. Li, Q. Fan, L. Wu, J. Shi and Y. Song, *Applied Surface Science*, 2018, **456**, 568–576.

3430 549 D. Saha, Y. Li, Z. Bi, J. Chen, J. K. Keum, D. K. Hensley, H. A. Grappe, H. M. Meyer, S. Dai, M. P. Paranthaman and A. K. Naskar, *Langmuir*, 2014, **30**, 900–910.

3432 550 D. Salinas-Torres, R. Ruiz-Rosas, M. J. Valero-Romero, J. Rodríguez-Mirasol, T. Cordero, E. Morallón and D. Cazorla-Amorós, *Journal of Power Sources*, 2016, **326**, 641–651.