bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Plenary) Wearable Sensors for Monitoring Chemical Markers: Beyond Steps and Vitals
Authors: Wang Joseph 
Published: July 2021

Wearable sensors have received a major recent attention owing to their considerable promise for monitoring the wearer's health and wellness. The medical interest for wearable systems arises from the need for monitoring patients over long periods of time. These devices have the potential to continuously collect vital health information from a person's body and provide this information to them or their healthcare provider in a timely fashion. Unlike early efforts aimed at monitoring mobility and vital signs, our recent efforts aim at filling the gaps by providing continuous biochemical information. The new chemical sensing wearable platforms provide new avenues to continuously and non-invasively monitor individuals and can thus tender crucial real-time information regarding a wearer's health. This presentation will discuss recent developments in the field of wearable electrochemical sensors integrated directly on the epidermis or within the mouth for various non-invasive biomedical monitoring applications [1-3]. Particular attention will be given to non-invasive monitoring of metabolites and electrolytes using flexible amperometric and potentiometric sensors, respectively, along with related materials, energy and integration considerations. Microneedle sensor arrays for multiplexed ISF monitoring will also be discussed also with wearable energy harvesters aimed to power these devices. The preparation and characterization of such wearable electrochemical sensors will be described, along with their current status and future prospects and challenges.
REFERENCES
[1] "Wearable Chemical Sensors: Present Challenges and Future Prospects" A. J. Bandodkar, I. Jeerapan, J. Wang, ACS Sensors, 2016, 1, 464.
[2] A. J. Bandodkar and J. Wang, "Non-invasive wearable electrochemical sensors: a review", Trends Biotechnol., 2014, 32, 363.
[3] "Wearable biosensors for healthcare monitoring", J. Kim, A. S. Campbell, B. Esteban-Fernández de Ávila, and J. Wang, Nature Biotechnology, 2019, 37, 389.
(Invited) Eight Channel Microphysiometry Using a Lab on a Chip Microclinical Analyzer
Authors: Cliffel David , Melow Sara , Miller Dusty , Tuladhar Pragun 
Published: July 2021

We have built a multianalyte microphysiometer that detects multiple analytes involved in the cellular bioenergetics simultaneously. Monitoring the uptake of glucose and oxygen, and the production of lactate and acid gives a more complete picture of the metabolic processes within the cell than just acidification microphysiometry alone. Metabolic processes such as glycolysis, mitochondrial ATP generation, and glycogenesis are all directly related to the flux of these analytes. Temporal resolution of metabolic responses is much faster than conventional well-plate studies, leading to dynamic metabolic data. Electrochemical sensors are easily adapted into microfluidic formats for microphysiology readouts.
Our newest instrumental designs include a complete overhaul of the microfluidic chambers, screen printed electrodes, and microfluidic pumps, valves, and drivers that will enable easy adoption of this methodology in the development of 3D cell and tissue studies using 8 separate electrochemical measurements at a time. In the first design, 8 separate amperometric sensors are developed using a screen printed electrode with isolated microfluidic channels. In the second design, 4 amperometric sensors are combined with 4 potentiometric sensors using the newly created CH1440 created by CH Instruments. The adaption of this technology to instrumenting organs-on-a-chip is currently underway.
Effect of Temperature on Methanol and Ethanol Measurement Using Noble Metal Doped Tin Oxide Sensors
Authors: Sun-Kou Rosario , Paredes-Doig Ana , Picasso Gino , La Rosa-Toro Adolfo , Doig-Camino Elizabeth 
Published: July 2021

In this work, the results of the sensing assays using the sensors based on tin oxide doped with Pd and Pt (0.1; 0.2; 0.3 and 0.5%) with and without zeolite coating are presented in contact with 3% methanol and 12% ethanol. In these assays, the stability and reproducibility of the sensing signal at different working temperatures (200, 220, 240, 260 and 280⁰C) were analyzed.
The intensity of the response signal of the sensors in contact mainly with solutions of 3% methanol and 12% ethanol was determined. And it was found that the working temperature with which the highest intensity in the response signal was obtained was 260 ⁰C. At this temperature the sensors with the best results were: 0.1% Pd / SnO2; 0.1% Pd / SnO2-Z; 0.2% Pd / SnO2-Z; 0.1% Pt / SnO2; 0.2% Pt / SnO2; 0.1% Pt / SnO2-Z and 0.2% Pt / SnO2-Z.
In most of the cases studied, it was observed that the sensing signal was repetitive and stable, maintaining its amplitude and shape during the analysis. However, at the temperature of 280 ° C the signal loses intensity and becomes distorted.
The response signals of the zeolite-coated sensors presented greater intensity and stability compared to those obtained with the same sensors without zeolite coating and with the tin oxide sensors without doping.
For example, in detecting 12% ethanol, as the sensing temperature increases from 200 ° C to 260 ° C, the sensitivity of doped sensors increases with respect to SnO2 and this effect is greater in sensors with zeolite coating. This is possibly due to the semiconductor nature of tin oxide that becomes more sensitive as the temperature increases, its surface becomes richer in electrons due to the increase of the more reactive species (O-adsorbed), which reacts with the alcohols (reducing substances), producing a flow of electrons towards the surface of the oxide that increases the conductivity of the sensor. This effect is increased by incorporating small amounts of palladium or platinum and adding a layer of zeolite. The sensing signal is not very stable and the distortion is greater at a temperature of 280 ° C where, in addition, a decrease in the intensity of the sensor response is observed.
A Nonenzymatic Electrochemical Nitrite Sensor Based on Nickel Phosphide Electrodeposited on Ni Foam
Authors: Lu Shun , Hummel Matthew , Jia Hongxing , Gu Zhengrong 
Published: July 2021

The detection of nitrite in drinking water and consumables is a critical process for preventing major threats to human health. While integral to normal body functions in low levels, large amounts of nitrite can result in poisoning in the short-term and the development of cancers over an extended period of time, due to nitrite’s interference with hemoglobin’s oxygen transport role in the blood by irreversible binding. Electroanalysis approach is regarded as a promising method to achieve excellent sensitivity and highly selectivity due to molecular redox on the surface of the working electrode. It has many benefits than spectrophotometry and high-performance liquid chromatography. It is note that, electrode modification is of importance for improving sensitivity and anti-interference performance in this process. However, conventional electrode modifications were mainly based on glassy carbon electrode or screen-print electrode. It is difficult to achieve the modified electrode’s maximum performance owing to the electrocatalyst is easily peeled off during electroanalysis. So, electrocatalyst grown on the electrode can fundamentally solve this problem without any conductive binder. In this abstract, a sensitive novel non-enzymatic nitrite electrochemical sensor based on nickel phosphide electrodeposited on Ni foam (NiP/NF) was described.
Results from our electrochemical investigations clearly demonstrate the excellent sensitivity and electrocatalytic activity of NiP/NF towards nitrite (Figure 1). The sensor has exhibited great electrochemical detection ability with a sensitivity of 1.56 × 10-4 mA μM-1, a linear range from 0.1 to 4000 μM and a detection limit of 0.01 μM (s/n = 3). These good performances can be attributed to the simple in-situ electrodeposition and great electrocatalytic performance of NiP. Moreover, good stability of the electrodeposited electrode can be ascribed to the in-situ growth route to construct a binder-free electrode. These results provide a new way to fabricate a novel electrochemical nitrite sensor. Further works will be carried out to investigate the properties of M-P, (M refers to Fe, Co, Mn, Cu, etc.) to detect nitrite.

Figure 1. Electrodeposition of NiP/NF and its electroanalysis toward nitrite. (a) Scheme of preparation of NiP/NF, (b) Electrodeposition process of NiP/NF, (c) SEM and mapping images of NiP/NF, and (d) Amperometric responses of nitrite on NiP/NF upon successive addition of nitrite to 0.1 M PBS (pH 7.0) under an applied potential of 0.8 V.

Figure 1
Strategies for Chemical Sensing Using High Purity Semiconducting Single-Walled Carbon Nanotube Electronic Devices
Authors: Lapointe Francois 
Published: July 2021

Semiconducting single-walled carbon nanotubes (sc-SWCNTs) are attractive in chemical sensing [1] because of their peculiarities: As they present a single atom-thick wall and a quasi 1D form factor, sc-SWCNTs are especially sensitive to their surroundings' electrostatics. Moreover, their band gap of approximately 1 eV is much greater than room-temperature thermal energy while being in a convenient range for electronic applications. Also, their electronic structure exhibits van Hove singularities (sharp spikes in the density of states) that drastically alters their conductivity and optical properties when charge carriers are injected. Although sc-SWCNT electronic devices are very sensitive, they lack in selectivity and they usually need to be functionalized to implement a lock-and-key detection mechanism.
In this talk, we will present various strategies for chemical sensing using enriched sc-SWCNTs. We will discuss the advantages and disadvantages of using sc-SWCNTs in electronic chemical sensing devices. Sub-ppm ammonia sensing will be demonstrated using a sc-SWCNT material wrapped with a decomposable polymer in a chemiresistor configuration. [2] Also using chemiresistors, CO2 detection has been achieved by designing a SWCNT-wrapping polymer with specific interactions. [3] Finally, we will present a strategy to differentiate the response of sensor elements to a variety of volatile analytes by changing the polymer gate dielectrics in a three-terminal bottom gate chemitransistor configuration. [4] This methodology opens the way to the implementation of sc-SWCNT-based chemitransistors in a printed cross-reactive sensor array.

References

[1] Schroeder, V. et al. Carbon Nanotube Chemical Sensors. Chem. Rev.
119, 599–663 (2019)
[2] Li, Z. et al. Decomposable s-Tetrazine Copolymer Enables Single-Walled Carbon Nanotube Thin Film Transistors and Sensors with Improved Sensitivity. Adv. Funct. Mater. 1705568 (2018)
[3] Guo, C. et al. Enrichment of Semiconducting Single-Walled Carbon Nanotubes with Indigo-Fluorene-Based Copolymers and Their Use in Printed Thin-Film Transistors and Carbon Dioxide Gas Sensors. ACS Sensors
5 2136–2145 (2020)
[4] Lapointe, F. et al. Carbon Nanotube Transistors as Gas Sensors: Response Differentiation using Polymer Gate Dielectrics. ACS Appl. Polym. Mater.
1 3269-3278 (2019)
Development of New Chemiluminescence Systems for Analysis
Authors: Xu Guoobao , Gao Wenyue , Saqib Muhammad 
Published: July 2021

Chemiluminescence (CL) is a light-emitting phenomenon as a result of chemical reactions. Luminol and lucigenin are typical CL luminophores, and hydrogen peroxide is typical coreactant. It is an important analytical technique because of its inherent features, such as high sensitivity, wide dynamic range, fast detection, simple equipment, and low instrumentation costs because no external light source or optics is needed. It has been extensively used for immunoassays, DNA detection, enzymatic biosensors, forensic bloodstain detection, pharmaceutical analysis, metal ion determination, imaging and so on. To improve performance of CL analysis and broaden the applications of CL, it is of great importance to develop new CL systems.
Herein, we present some new CL systems such as artemisinin/luminol, thiourea dioxide/luminol, N-hydroxyphthalimide/luminol, hydroxylamine-O-sulfonic acid/luminol, allantoin/ lucigenin and creatinine/H2O2 systems. We will also demonstrate their applications in forensic bloodstain detection, enzyme detection, metal ions detection, and so on [1-3].
Acknowledgment
We are grateful for financial support from the National Key Research and Development Program of China (No. 2016YFA0201300), National Natural Science Foundation of China (Nos. 21874126,21675148), the Chinese Academy of Sciences (CAS)-the Academy of Sciences for the Developing World (TWAS), President’s Fellowship Program, and the CAS President's International Fellowship Initiative (PIFI) project.
References
(1) Wenyue Gao, Chao Wang, Kateryna Muzyka, Shimeles Addisu Kitte, Jianping Li, Wei Zhang and Guobao Xu*. Artemisinin-luminol chemiluminescence for forensic bloodstain detection using smart phone as detector. Anal. Chem., 2017, 89 (11), 6160–6165.
(2) Wenyue Gao, Wenjing Qi, Jianping Lai, Liming Qi, Saadat Majeed and Guobao Xu*. Thiourea dioxide as unique eco-friendly coreactant of luminol chemiluminescence for sensitive detection of luminol, thiourea dioxide, and cobalt ions. Chem. Commun., 2015, 51(9), 1620–1623.
(3) Muhammad Saqib, Liming Qi, Pan Hui, Anaclet Nsabimana, Mohamed Ibrahim Halawa, Wei Zhang,* Guobao Xu*. Development of luminol-N-hydroxyphthalimide chemiluminescence system for highly selective and sensitive detection of superoxide dismutase, uric acid and Co2+. Biosens. Bioelectron., 2018, 99, 519-524.
Near Infrared Fluorescent Nanomaterials for Biosensing Applications
Authors: Mann Florian , Selvaggio Gabriele , Nissler Robert , Kruss Sebastian 
Published: July 2021

Nanomaterials have novel properties due to quantum confinement and high surface areas and are therefore interesting for both fundamental studies and applications. One important property of many nanomaterials is fluorescence, which provides insights into electronic structure and local chemical processes. Additionally, fluorescence is a valuable tool to detect biomolecules. We are interested in 1D and 2D near infrared (NIR) fluorescent materials because this region of the spectrum (800 nm -1700 nm) promises ultra-low background and scattering. One example are semiconducting single-walled carbon nanotubes (SWCNTs). We developed different non-covalent concepts and quantum defects to tailor the organic phase around SWCNTs and tune both molecular interactions and photophysics. It allowed us to understand mechanistically how conformational changes of the organic phase affects the NIR fluorescence spectra of the SWCNTs. These functionalized SWCNTs can be used to detect and label (bio)molecules over multiple length scales: Single proteins, release of signaling molecules such as neurotransmitters from cells and stress (reactive oxygen species) in plants. Another example are 2D NIR fluorescent silicate nanosheets that have size-dependent fluorescence lifetimes in the µs range and enable lifetime-encoded fluorescence microscopy and detection methods.
In summary, we present fundamental insights into the engineering of NIR fluorescent materials and their interfaces and the potential for biosensing.
Direct Analysis of Proteins in Physiological Samples with Three-Dimensional Paper-Based Isoelectric Focusing
Authors: Niu Jicheng , Li Fei 
Published: July 2021

Point-of-care testing (POCT) of proteins is crucial for on-site and rapid diagnosis of diseases in community and family medicine. Microfluidic paper-based analytical devices (µPADs) have attracted growing attention in POCT of proteins, while the practical applications of µPADs in the analysis of proteins in physiological samples is still limited as physiological samples are usually high-salt and complex. Herein, we developed a three-dimensional (3D) paper-based isoelectric focusing (IEF) platform, which is composed of power supply, reservoirs and separation channel make by origami and stacking of cellulose acetate membrane, to simultaneously separate and enrich proteins in both low-salt samples and high-salt samples, especially for directly pretreating and analyzing proteins in physiological samples. Under the optimized experimental conditions, standard proteins (Phy and BHb) were separated in 18 min under a 36.0 V power supply and obtained 10-fold enrichment using the 3D paper-based IEF platform. Then, the capability of the 3D paper-based IEF platform with using a 12.0 V battery as power supply for direct pre-treatment of high-salt samples was proven through separating three standard proteins in saline (0.9 % NaCl) with separation resolution (SR) >1.29. Through further coupling with colorimetric and lateral flow strip measurements, the 3D paper-based IEF platform was applied to directly pre-treat and quantitatively analyze the two disease biomarkers, i.e., microalbuminuria and C-reactive proteins in clinical human serum. The analytical results had the relative deviations of <8.4% and <13.1% to clinical results, respectively. As the first report of the paper-based IEF platform for directly pretreating high-salt samples, this work proposes a new strategy to minimize the difficulty of directly processing high-salt samples with traditional IEF system and provides a versatile, miniaturized and low voltage demand analytical platform for POCT of proteins in physiological samples.

References

[1] J. C. Niu, T. Zhou, L. L. Niu, Z. S. Xie, F. Fang, F. Q. Yang, Z. Y. Wu, Simultaneous Pre-concentration and Separation on Simple Paper-based Analytical Device for Protein Analysis, Analytical and Bioanalytical Chemistry 410.6 (2018): 1689-1695.
[2] J. C. Niu, H. X. Shi, H. G. Wei, B. Gao, J. X. Li, F. Xu, X. G. Li, F. Li, Liquid Plasticine Integrated with Isoelectric Focusing for Miniaturized Protein Analysis, Analytical Chemistry 92.13 (2020): 9048–9056.
Rationally Designed Molecularly Imprinted Polymers for Trace Electroanalysis of Environmental Micropollutants
Authors: Glasscott Matthew William , Moores Lee C , Fernando Ashvin , Shukla Manoj , Jenness Glen , Schutt Timothy , Bresnahan Caitlin 
Published: July 2021

The undetected discharge of solubilized micropollutants into natural waterways constitutes a major public health concern. Thus, generalizable strategies to detect various micropollutant species coupled with deployable sensing platforms are paramount for indicating the presence of contamination at its earliest onset. Benchmark chromatographic methods paired with mass spectrometry to quantify micropollutants are expensive and difficult to deploy into waterways as passive environmental probes. In contrast, electrochemical sensors are inexpensive and easily miniaturized. We report the electrochemical detection of two compounds, 2,4,6-trinitrotoluene (TNT), a prevalent munition, and 2,4-dichlorophenoxyacetic acid (2,4-D), a common fertilizer, using molecularly imprinted polymers (MIPs). MIPs were rationally designed using DFT-level molecular simulations to determine an ideal functional monomer with maximal affinity for each micropollutant species. NMR titration methods were used to verify the simulation results and optimize the monomer/micropollutant ratio. Following optimization, MIPs were synthesized by anodic electropolymerization onto gold substrates in the presence of the micropollutant, which was subsequently stripped away via solvent washing to reveal micropollutant-specific binding sites. Upon micropollutant association with the MIP when placed in contaminated water, surface sites were blocked, which was tracked electrochemically. Each sensor exhibited a limit of detection in the sub-parts-per-billion regime, demonstrating the amenability of this sensing method for trace analysis. Combining the sensitivity of electroanalysis with the selectivity provided by the MIP recognition element constitutes a powerful platform for the detection of micropollutants in environmental matrices.
FIGURE CAPTION:
Electroanalytical signal obtained following the adsorption of TNT or 2,4-D molecules to an electropolymerized molecularly imprinted polymer (MIP) recognition element. MIPs may be rationally designed using density functional theory (DFT, inset) to maximize the monomer/toxin binding affinity, enhancing the analytical response and permitting the sub-ppb quantification of these toxins in environmental matrices.

Figure 1
Xanthogen Polysulfides As Active Materials for Rechargeable Batteries
Authors: Bhargav Amruth , Manthiram Arumugam 
Published: July 2021

Significant research strides taken in the past decade have shown that lithium-sulfur (Li-S) batteries are a promising technology to compete with current Li-ion batteries owing to their significantly higher specific energy. However, some fundamental and technical challenges, such as the polysulfide shuttle effect and the need for abundant electrolyte for battery operation, have beleaguered Li-S batteries from being the next practical high-energy-density solution.[1] Recent resurgence of Li-organosulfur batteries as alternative sulfur-based cathode chemistry has shown great potential to alleviate some of these challenges.[2] These materials offer control over the order of the lithium polysulfides formed during cycling through the presence of organic terminal groups, thus minimizing the polysulfide shuttle effect. Additionally, they possess the ability to operate under lean-electrolyte conditions, a critical parameter for maximizing cell-level specific energy.
This work introduces a new member into the family of organosulfur cathode materials – xanthogen polysulfides. Diisopropyl xanthogen polysulfide (DIXPS) was used as a model compound to understand the electrochemical characteristics of this new material class. Its chemical transformations within a battery will be discussed. DIXPS shows excellent long-term performance with stability up to 1,000 cycles at a high rate of 4C. DIXPS also demonstrates the ability to deliver a high specific energy of 1,313 W h kg-1 and 1,694 W h L-1 while operating under high-loading and lean-electrolyte conditions. This illustrates the practical applicability of this material. Additionally, the feasibility of using alternate anodes such as sodium-metal will also be explored. The ability to synthesize such battery materials using natural feedstocks, such as sugars and alcohols will also be examined.

References:

[1] A. Bhargav, J. He, A. Gupta, A. Manthiram, Joule
2020, 4, 285.
[2] D. Y. Wang, W. Guo, Y. Fu, Acc. Chem. Res.
2019, 52, 2290.

Figure 1