bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Local Graphitization on the Charging Mechanisms of Capacitive Microporous Carbon Supercapacitor Electrodes Application
Authors: Yin Huan , Shao Hui , Taberna Pierre Louis , Yin Huan
Published: July 2022

Electrochemical double layer capacitors (EDLCs) store the charge by reversible adsorption of ions at the electrode/electrolyte interface. The optimization of EDLC performance needs to push further our basic understanding of the ion fluxes that occur during the charging/discharging process. Microporous carbon has been widely used as supercapacitor electrode material thanks to their tunable porosity and high specific surface area. However, most of the porous carbon materials have complex carbon structures, so that the mechanism is still poorly understood.

Using electrochemical quartz crystal microbalance technique (EQCM) technique, we studied the charge storage mechanisms of two nanoporous carbide-derived carbon (TiC-CDC) electrodes, namely CDC-800 synthesized at 800℃ and CDC-1100 synthesized at 1100℃. These two carbons have a similar porosity but the CDC-1100 sample shows more graphitic carbon microstructure. We found that a counter-ion adsorption process mainly controls the charging mechanism of CDC-800 (“V” shape m vs Q plot), while an expanded ion-exchange and counter-ion adsorption process is obtained for CDC-1100 (“U” shape). We show here that the local carbon structure affects the charging mechanism of electrical double layer capacitance, and a strong interaction between the anions and graphitic carbons explains these different behaviors. Our results provide more insights into the fundamental understanding of the carbon/electrolyte interface and the charge of the electrical double layer capacitance.

Figure 1. Electrode mass change versus charge during the polarization of CDC-800 (a) and CDC-1100 (b) coated Au electrodes in 2M EMI-TFSI/ACN electrolyte at the scan rate of 10 mV·s−1.

Figure 1
(Nanocarbons Division SES Young Investigator Award) Synthetic Biology Approaches for Overcoming Bottlenecks in Optical Nanocarbon Technologies
Authors: Boghossian Ardemis Anoush
Published: July 2022

Bioengineering is the synthetic biologist’s approach to engineering new materials. It has allowed researchers to overcome billions of years of evolution to create unnatural biomolecules that have been programmed to interface with synthetic materials or optimized to bind analytes through interactions unfounded in nature. Biomolecules offer unparalleled molecular recognition that can be tuned by engineers to create highly specific sensors. Unfortunately, biology has its limits; many biological optical sensors rely on fluorophores that photobleach, which limit sensor lifetime, at visible emission wavelengths that overlap with tissue absorption. Unlike these fluorophores, semiconducting single-walled carbon nanotubes (SWCNTs) benefit from fluorescent emissions that are indefinitely photostable, demonstrating sensitivities that can detect analytes down to the single molecule. Their near-infrared fluorescence wavelengths are also transparent to tissue absorption, allowing for continuous in vivo sensing. Unfortunately, these nanomaterials lack the molecular recognition biology has to offer.

In a sense, the advantages and disadvantages posed by the fields of bio- and nano-materials engineering are highly complementary. This seminar focuses on the development of a new generation of NanoBiOptic devices – devices that exploit the synergy of nano-bio hybrids – for sensing applications. We apply bioengineering techniques, such as directed evolution and artificial nucleic acid design, to circumvent current approaches used to engineer SWCNT-based sensors. In demonstrating these techniques, we realize several previously intractable platforms for bioanalyte detection and for optically monitoring various biomolecular interactions. Thus, by reprogramming biological materials to behave in an otherwise non-natural manner, synthetic biology has the potential to complement the physical sciences in the engineering of new synthetic optical platforms.
(Invited) Developing Optical Nanosensors for the Early Detection of Gynecologic Cancers
Authors: Yaari Zvi A , Yang Yoona , Zheng Ming , Jagota Anand , Heller Daniel A.
Published: July 2022

Uterine and ovarian cancer patients' prognosis and quality of life are significantly affected by the failure to diagnose the disease accurately. Early detection may save more than 80% of women diagnosed with ovarian cancer. Therefore, developing new platforms for better detecting potential biomarkers in both biofluid samples and in-situ may significantly improve early detection and better survival. Here we propose two platforms to detect multiple cancer biomarkers in cancer patients' specimens and detect specific biomarkers in-situ using implantable sensors. These technologies harness the unique optical properties of single-walled carbon nanotubes (SWCNTs)-based sensors and artificial intelligent algorithms. We developed an array of DNA-SWCNT sensors that composed a library of ssDNA sequences and multiple chiralities of SWCNTs to detect various biomarkers within patient clinical samples. Harnessing machine learning algorithms to process the optical response of the sensors enabled the precise detection of the unique spectroscopic fingerprints of each of the biomarkers in uterine washing clinical samples. For detecting biomarkers within the uteri of the patients, we developed an implantable sensor that serves as an implantable intrauterine device. The sensor can detect cancer biomarkers and differentiate between benign and malignant cases.
Development of Organic Color Center Based Nanosensors for Proinflammatory Cytokine Detection
Authors: Kim Mijin , McCaan Jim , Chen Chen , Randall Ewelina , Koder Ronald , Heller Daniel
Published: July 2022

Organic color centers, also known as fluorescent sp3 quantum defects, on single walled carbon nanotubes, have opened exciting opportunities to re-engineer the optical and electronic properties of carbon nanotubes via covalent surface chemistry. Organic color centers produce molecularly tunable fluorescence in the near-infrared, conferring new chemical and optical functionalities that are suitable for biosensing applications. In this talk, we discuss the strategies that enhance the physical stability and optical response of the nanosensors for robust, transient detection of proinflammatory cytokines in biofluids. The sensor technology incorporates functional organic color centers augmented by biodesigned supercharged molecular recognition proteins.
(Invited) A Carbon Nanotube-Based Sensor Paint to Image Cellular Signaling
Authors: Kruss Sebastian
Published: July 2022

Cells use molecules to exchange information. A very prominent example is neurotransmitter signaling between neuronal cells The neurotransmitter dopamine is released from discrete axonal structures called varicosities. Its release is essential in behaviour and is critically implicated in prevalent neuropsychiatric diseases. Existing dopamine detection methods are not able to detect and distinguish discrete dopamine release events from multiple varicosities. This prevents an understanding of how dopamine release is regulated across populations of discrete varicosities. Using a near infrared fluorescent (980 nm) dopamine nanosensor ‘paint’ (AndromeDA) based on single-walled carbon nanotubes (SWCNTs), we show that action potential-evoked dopamine release is highly heterogeneous across release sites and also requires molecular priming. Using AndromeDA, we visualize dopamine release at up to 100 dopaminergic varicosities simultaneously within a single imaging field with high temporal resolution (15 images/s). We find that ‘hotspots’ of dopamine release are highly heterogeneous and are detected at only ~17% of all varicosities. In neurons lacking Munc13 proteins, which prime synaptic vesicles, dopamine release is abolished during electrical stimulation, demonstrating that dopamine release requires vesicle priming. In summary, AndromeDA reveals the spatiotemporal organization of dopamine release.
(Invited) Engineering Antibodies Fragments for Continuous Protein Biosensing
Authors: Corrie Simon , Fercher Christian , Islam Jiaul , Jones Martina , Mahler Stephen
Published: July 2022

Developing new approaches to monitor critical analytes in complex biological environments is key to the development of new diagnostic tools for application in a range of fields including the biomedical, environmental and food sciences. While reversible ion and metabolite sensing can be achieved through a variety of approaches including ionophore-based techniques, there is a lack of approaches to achieve real-time protein monitoring. Immunoassays (e.g. ELISA) are robust approaches to achieve endpoint measurements, however the multi-step nature of the technique is not amenable to reversible biosensing. One approach to simplify immunoassay chemistry is to reduce the number of assay steps required, which could lead to simpler manual assays, less reliance on laboratory infrastructure, or simpler POC designs.

We have developed a biosensor approach based on direct detection of antigen-antibody binding in a single step. Using a site-specific approach to incorporate fluorescent dyes into antibody fragments, we screened a range of positional mutants and identified several that showed antigen-dependent spectral changes. These changes were observed to be dose-dependent in both buffer and diluted plasma samples. We then applied a site-directed mutagenesis approach to generate antibody fragments capable of reversible protein interactions and reversible sensing. These fragments can be used in homogenous assays or immobilised to surfaces, and in this presentation we will present our most recent results on epidermal growth factor receptor (EGFR) and cardiac troponin I (cTnI) monitoring.
(Invited) Carbon Nanotubes for Plant Genetic Engineering
Authors: Demirer Gozde S , Zhang Huan , González Grandío Eduardo , Landry Markita P
Published: July 2022

Plants will benefit from genetic engineering to feed our growing global population in the midst of climate change, to provide our most clinically-relevant drugs, and for our environmental remediation efforts. New generation genome engineering technologies, such as CRISPR/Cas, hold the potential to alter plant genes in a precise and targeted manner. The first step of any plant genetic engineering application is to deliver important biomolecular cargoes into the desired subcellular locations of plant cells. However, the limitations of traditional plant gene delivery methods, i.e. Agrobacterium and gene gun, prevent plant genetic engineering from reaching its full potential.

Given the lack of efficient biomolecule delivery vehicles to plants and potential impact of plant biotechnology on food security and sustainability, we developed nanoparticle-based platforms to efficiently deliver small interfering RNA1,2 and plasmid DNA3,4 cargoes into plant cells in a species-independent manner, which eliminates the use of gene gun and addresses the main delivery bottlenecks of plant genetic engineering. We show that pristine single walled carbon nanotubes (SWCNTs) can adsorb small interfering RNA molecules through pi-pi stacking for plant delivery, whereas a covalently modified and positively charged SWCNT platform is more efficient for large double-stranded DNA delivery to mature plant leaf cells.

This talk will first briefly summarize the development, characterization and biological verification of each nanoparticle platform for plant delivery applications. Next, I will present our recent results of CRISPR/Cas gene editing in plant leaves using the SWCNT DNA delivery platform5. The talk will be concluded by discussing the several assays performed to demonstrate the effect of nanoparticles on plant health, including an RNA-sequencing analysis of nanoparticle-treated plant leaves6. We believe the SWCNT delivery technologies that are discussed in this talk will have an immense impact on food security and sustainability by enabling the generation of improved plants that can rapidly reach the market in a cost-effective manner.

Demirer G.S.*, Zhang H.* et al., DNA Nanostructures Coordinate Gene Silencing in Mature Plants. PNAS (2019).

Demirer G.S. et al., Carbon Nanocarriers Deliver siRNA to Intact Plant Cells for Efficient Gene Knockdown. Science Advances (2020).

Demirer G.S. et al., High Aspect Ratio Nanomaterials Enable Delivery of Functional Genetic Material Without Transgenic DNA Integration in Mature Plants. Nature Nanotechnology (2019).

Demirer G.S. et al., Carbon nanotube–mediated DNA delivery without transgene integration in intact plants. Nature Protocols (2019).

Demirer G.S. et al., Nanotechnology to advance CRISPR–Cas genetic engineering of plants. Nature Nanotechnology (2021).

González-Grandío E., Demirer, G.S. et al. Carbon nanotube biocompatibility in plants is determined by their surface chemistry. bioRxiv (2021).
Detection and Imaging of the Plant Pathogen Response By Near Infrared Fluorescent Polyphenol Sensors
Authors: Nissler Robert , Müller Andrea , Dohrman Frederike , Kurth Larissa , Li Han , Cosio Eric , Flavel Benjamin S , Giraldo Juan Pablo , Mithöfer Axel , Kruss Sebastian
Published: July 2022

Plants use secondary metabolites such as polyphenols for chemical defense against pathogens and herbivores. Despite their importance in plant pathogen interactions and tolerance to diseases, it remains challenging to detect polyphenols in complex plant tissues. Here, we create molecular sensors for plant polyphenol imaging that are based on near-infrared (NIR) fluorescent single wall carbon nanotubes (SWCNTs). We identified polyethylene glycol-phospholipids that render (6,5)-SWCNTs sensitive (Kd = 90 nM) to plant polyphenols (tannins, flavonoids, ...), which red-shift (up to 20 nm) and quench their emission (~1000 nm). These sensors report changes in total polyphenol level after herbivore or pathogen challenge in crop plant systems (Soybean Glycine max) and leaf tissue extracts (Tococa spp). We furthermore demonstrate remote chemical imaging of pathogen-induced polyphenol release from roots of soybean seedlings over the time course of 24h. Additional use of chirality-pure polyphenol sensors gives further access to ratiometric sensing and imaging applications. Overall, this approach allows in situ visualization and understanding of the chemical plant defense in real time and paves the way for plant phenotyping for optimized polyphenol secretion.
(Digital Presentation) Realistic Molecular Dynamics Modeling of ssDNA/SWCNT Hybrids
Authors: Alizadehmojarad Ali A. , Bachilo Sergei M. , Kolomeisky Anatoly , Weisman R. Bruce
Published: July 2022

Despite the importance of single-wall carbon nanotubes (SWCNTs) coated with short oligos of single-stranded DNA (ssDNA), the structure-specific interactions in these hybrids remain poorly understood. It is known that the interactions can depend on the DNA base sequence and length, and on the nanotube diameter and roll-up angle. To study these phenomena, we are applying a combination of computational and experimental methods. A major goal for guiding and validating molecular dynamics simulations of the hybrid structures is finding the average length of nanotube covered by each ssDNA oligo. We have quantified this by carefully preparing dialyzed aqueous dispersions of SWCNTs in specific oligos and then measuring the absolute mass concentrations of both components using total organic carbon analysis. Corresponding absorption spectra were also measured to deduce ultraviolet SWCNT molar absorptivities (structurally averaged), which in combination with known ssDNA nucleobase absorptivities allow quicker determinations of mass ratios in the hybrids. Our results for a library of hybrids indicate that purine nucleobases on average cover a larger region on the nanotube surface than do pyrimidine nucleobases, as is consistent with the sizes of those aromatic structures. This average coverage is key to developing realistic atomistic molecular dynamics models for the conformations of ssDNA adsorbed on SWCNT sidewalls. Examples of such computed hybrid structures and their significance will be presented.
An Algorithmic Approach for Developing Single-Walled Carbon Nanotube Optical Sensors Against Adulterants in Aquaculture
Authors: Gong Xun , Renegar Nicholas , Cho Soo-Yeon , Levi Retsef , Strano Michael
Published: July 2022

The nanoparticle corona phase (CP) offers a unique materials design space for constructs capable of molecular recognition (MR) for sensing applications. Single-walled carbon nanotube (SWCNT) CPs have the additional ability to transduce MR through its band gap photoluminescence (PL). DNA oligonucleotides are well-known to disperse SWCNTs through forming CPs and can be manufactured with molecular precision. Nevertheless, no generalized scheme exists for the de novo prediction of SWCNT MR based on these CPs due to their sequence-dependent three-dimensional complexity.

In aquaculture, there exist a pressing need for rapid tests for the detection of commonly harmful adulterants such as metal ions and small molecule antibiotics. Through a screening process, we found that DNA-SWCNTs offer a rich design space for MR capable of differentiating divalent metal ions. We also created best practices for the study of colloidal SWCNT analyte responses involve mitigating the effects of ionic strength, dilution kinetics, laser power and analyte response kinetics.

Next, we generated the largest DNA-SWCNT PL response library of 1408 elements against 4 adulterant targets. We leveraged machine learning (ML) techniques and used both local features (LFs) and high-level features (HLFs) of the DNA sequences were utilized as model inputs. Out-of-sample analysis of our ML model showed significant correlations between model predictions and actual sensor responses for 6 out of the 8 tested experimental conditions. Furthermore, models utilizing both LFs and HLFs show improvement over that with HLFs alone, demonstrating that DNA-SWCNT CP engineering is more complex than simply specifying general DNA molecular properties. Taken as a whole, we detail the feasibility and utility of a ML-guided approach for nanoparticle CP engineering with relatively few experiments within a high-dimensional design space.
(Invited) Hyperspectral Detection of the Fluorescence Shift between Enantiomers of Empty and Water-Filled Single-Wall Carbon Nanotubes
Authors: Wenseleers Wim , Erkens Maksiem , Lopez Carrillo Miguel Angel , Botka Bea , Cambre Sofie , Duque Juan
Published: July 2022

The unusually chiral-structure-dependent properties of single-wall carbon nanotubes (SWCNTs) are also strongly influenced by their internal and external environment, which can therefore be investigated through optical spectroscopy.[1,2] In order to study this influence in detail, we developed a hyperspectral IR fluorescence imaging setup based on a microscope with a liquid crystal tunable filter. By resolving the spectra of individual SWCNTs, and even along the length of SWCNTs, the effect of inhomogeneous broadening is largely eliminated, and spectral details can be resolved which are inaccessible in bulk spectroscopy. An automated image processing scheme is used to obtain statistics on large numbers of individual SWCNTs. In particular, we show that not only the spectral shift in emission between empty and water-filled[1] chirality sorted SWCNTs can be resolved, but even separate emission peaks are observed for the left- and right-handed enantiomers, which interact slightly differently with the chiral surfactant with which they are coated. The approach is particularly promising for the quantification of enantio-selective separation results.

[1] W. Wenseleers et al., Adv. Mater. 19, 2274 (2007); S. Cambré and W. Wenseleers, Angew. Chem. 50, 2764 (2011); S. Cambré et al., ACS Nano
6, 2649 (2012).

[2] J. Campo et al., ACS Nano 2021, 15, 2301−2317.
(Invited) Controlling the Synthesis of Organic Color-Centers on sp2 Carbon Lattices
Authors: Wang YuHuang , Qu Haoran , Fortner Jacob , Wang Peng
Published: July 2022

Organic color-centers (OCCs) are opening exciting opportunities at the forefronts of bio-imaging, molecular sensing, and quantum information sciences. However, the chemistries used to generate these sp3 quantum defect emitters typically produce diverse bonding configurations that are poorly understood, posing a formidable challenge to the synthesis of identical color centers. In this talk, we will report our progress at addressing this synthetic challenge. Both challenges and opportunities will be discussed.
Single-Walled Carbon Nanotubes Charge Management By Controlled Functionalization
Authors: Setaro Antonio , Fiebor Alphonse , Adeli Mohsen , Reich Stephanie
Published: July 2022

Managing the density of charges in carbon nanotubes opens new ways to tune their optical response, their transport properties, and their physico-chemical features. Charge transfer from molecules adsorbed onto the sidewall or filled within the hollow cavity of the nanotubes has already been demonstrated, yet a fine-tunable control of the surface coverage/filling fraction (and thus the amount of transferred charge) remains challenging to achieve. Alternatively, we developed an optically nonperturbing covalent functionalization technique based on the inclusion of a triazine derivative into the carbon network [1]. The nitrogen atom sustaining the attached group becomes an integrated part of the pi-conjugated network and contributes with its lone electron pair to uplifting the position of the Fermi level of the tube. Since the density of attached groups can be varied by adapting the synthetic conditions, this technique offers the advantage of controlling the amount of charge injected into the tubes. Additional groups attached onto the other end of the triazine moiety, moreover, are able to inject charge into the tubes as well. This, for example, allowed us to modulate the photoluminescence of the tubes, switching their emission on and off through the attachment of the switchable spiropyran/merocyanine system [2]. Here we focus on a class of charge-transfer agents that either donate or withdraw electrons depending on the arrangements of their building units [3] and how their decoration affects the properties of the tubes.

Figure: Different number of methoxy groups can be attached onto aniline at different positions, resulting in compounds that can either donate or withdraw electrons from the tubes they are attached onto [3].

[1] Setaro et al. Nature Communications 8,
14281 (2017).

[2] Godin et al. Science Advances 5,
eaax1166 (2019).

[3] Fiebor et al. J. Phys. Chem. C. 125, 19925 (2021).

Figure 1
Exploring the Role of Photosensitizer in Guanine Functionalization of Single-Wall Carbon Nanotubes
Authors: Soltani Nima , Bachilo Sergei M. , Weisman R. Bruce
Published: July 2022

Single-walled carbon nanotubes (SWCNTs) have attracted a great deal of attention during the past two decades because of their unique optoelectronic properties and their potential applications in biomedical theranostics as well as nanoelectronics. It was recently discovered that it is possible to spatially modulate the exciton band gap of carbon nanotubes through a process known as guanine functionalization. In this reaction, the guanine nucleotides of an ssDNA strand wrapping a nanotube become covalently bonded to sidewall carbon atoms upon exposure to singlet oxygen.1 In the original work, the authors used xanthene derivatives such as rose bengal and erythrosine B as photosensitizers in order to generate singlet oxygen. It was assumed that this process was an independent step that did not involve the nanotube. However, we have found that rose bengal has a strong tendency to form a charge transfer complex with SWCNTs, and these complexes appear to be essential in the functionalization reaction.

We have studied the complexation through a spectroscopic study of SWCNT fluorescence quenching and the appearance of a charge transfer absorption feature near 600 nm. Both are interpreted as results of nanotube p-doping when the dye adsorbs to the sidewall. We also observe that the charge transfer complex formation accelerates when the rose bengal is optically excited, apparently proceeding through the dye’s triplet state. A correlation between extent of guanine functionalization and the concentration of charge transfer complexes is found as ionic strength is changed. We infer that the functionalization reaction is enabled by adsorbed photosensitizers. Interestingly, the extent of SWCNT fluorescence quenching by rose bengal is found to vary significantly with (n,m) structure. This quenching effect therefore provides a simple approach to monitor structure-specific interactions between SWCNTs and coatings, including ssDNA and conventional ionic surfactants.

(1) Zheng, Y.; Bachilo, S. M.; Weisman, R. B. Controlled Patterning of Carbon Nanotube Energy Levels by Covalent DNA Functionalization. ACS Nano
13, 5222 (2019). https://doi.org/10.1021/acsnano.9b03488.
(Invited, Digital Presentation) Ortho-Substituent Structure Design in Aryldiazonium Salts for Defect Photoluminescence Modulation of Locally Functionalized Single-Walled Carbon Nanotubes
Authors: Shiraki Tomohiro , Yu Boda , Naka Sadahito , Kato Koichiro , Fujigaya Tsuyohiko
Published: July 2022

Photoluminescence (PL) of single-walled carbon nanotubes (SWCNTs) appears in the near infrared (NIR) region, which is applicable to advanced optical applications such as bioimaging and telecommunication devices. Local chemical functionalization of SWCNTs has been gathering great attention because of the enhancement of their NIR PL properties. Therein, defects such as sp3 carbon are locally doped to the crystalline sp2 carbon network of the tube walls by the chemical functionalization process.[1-4] As a result, the locally functionalized SWCNTs (lf-SWCNTs) emit new PL with red-shifted wavelengths and increased quantum yields from the doped sites (E
11* PL) compared to original E
11 PL of pristine SWCNTs. It is due to the doping effects to change electronic structures for narrower bandgap formation, by which mobile excitons in the tubes are trapped at the doped sites to be localized states for efficient PL conversion.

The chemical functionalization approach allows us to use various chemical reactants for the doped site formation in lf-SWCNTs. The molecular effects including structural differences and molecular binding functions have resulted in versatile NIR PL wavelength modulation of lf-SWCNTs.[1-4] We have reported that E
11* PL generation phenomena were significantly varied depending on isomeric structures of substituted aryldiazonium salts (AD) used for lf-SWCNT synthesis.[5] Especially, ortho-substituted ADs (oADs) produced two PL around 1100 and 1250 nm-regions, respectively for the resulting lf-SWCNTs with (6,5) chirality. Here, we apply various substituent design for oADs and examine the substituent structure effects in terms of modulation of the PL emission properties of lf-SWCNTs. For example, oAD having a phenyl substituent resulted in enhancement of the ~1250 nm PL contribution. Other substituent effects are observed depending on substituent structures of oADs, from which interactions between the substituents and the tubes are considered to induce the observed PL spectral changes. The result indicates that local chemical functionalization using oAD has a high potential to largely modulate NIR PL wavelengths of lf-SWCNTs beyond 1000 nm regions.

[1] T. Shiraki et al. Acc. Chem. Res., 53, 1846 (2020). [2] S. Tretiak et al., Acc. Chem. Res., 53, 1791(2020) [3] Y. Wang et al. Nat. Rev. Chem., 3, 375 (2019). [4] T. Shiraki, Chem. Lett., 50, 397 (2021). [5] T. Shiraki et al. Chem. Commun., 53, 12544 (2017).
(Invited) Theoretical Insight into New Strategies of Carbon Nanotube Functionalization
Authors: Tretiak Sergei
Published: July 2022

An intentional introduction of quantum defects to the single-walled carbon nanotube (SWCNT) surface leads to unique photoluminescence properties that may be useful for a wide range of optoelectronic, sensing, imaging and quantum communication applications. Quantum-chemical simulations help to rationalize spectroscopic observation and fine tune synthetic strategies. I will overview photosynthetic control of chemical binding configurations of quantum defects through the spin multiplicity of photoexcited intermediates. Here photoexcited aromatics react with SWCNT sidewalls to undergo a singlet-state pathway in the presence of dissolved oxygen, leading to ortho binding configurations of the aryl group on the nanotube. In contrast, the oxygen-free photoreaction activates previously inaccessible para configurations through a triplet-state mechanism. To understand the atomistic mechanism of these photo-activated reactions and their dependence on spin multiplicity, we have modeled the reaction with and without triplet quenching using density functional theory. Computed reaction pathways demonstrate selectivity and dependence of outcomes of the photo-activated reaction on the presence or absence of triplet quenching, corresponding to presence or absence of oxygen, respectively. Such spin-selective photochemistry diversifies SWCNT emission tunability by controlling the morphology of the emitting sites.
(Invited) Hybridization of Dark Excitons, Bright Excitons, and Photons in an Ultrastrongly Coupled Carbon Nanotube Microcavity and the Importance of Sub-Radiant Polariton States during Relaxation
Authors: Arnold Michael S.
Published: July 2022

This talk will present on strong light-matter interaction in optical microcavities incorporating dense semiconducting carbon nanotubes, characterizing hybridization of the bright and dark exciton states of nanotubes, mediated by a cavity photon plus exciton-phonon coupling. This talk will also present on the relaxation of optically excited, bright polariton modes into sub-radiant dark polaritons.
(Invited) Optically Detected Magnetic Resonance of Triplet Excitons in Sorted (6,5) and (7,5) SWCNTs
Authors: Cambre Sofie , Sudakov Ivan , Goovaerts Etienne , Blackburn Jeff , Duque Juan , Wenseleers Wim
Published: July 2022

Single-wall carbon nanotubes (SWCNTs) possess unique electronic and optical properties, strongly depending on their exact chiral structure. Their quasi one-dimensional character results in the formation of strongly bound electron-hole pairs (excitons) that can even be observed at room temperature (i.e. binding energies of the order of several hundred meV).[1] The exciton fine structure of SWCNTs is quite complex, with multiple singlet and triplet excitonic states, of which only one is optically allowed, thereby resulting in extremely low fluorescence (PL) quantum yields. While the singlet excitons have already been investigated thoroughly, little is known about the longer-living triplet excitons.

In this work, we report the characterization of triplet excitons in chirality-purified samples of (7,5) and (6,5) SWCNTs by means of optically detected magnetic resonance spectroscopy (ODMR), a technique that measures the influence on the emission of CNTs when making transitions between the spin levels of the triplet excitons. In both chiralities the nanotubes are shown to sustain two types of triplet exciton states, as shown by the symmetry and magnitude of their zero-field splitting parameters in the spin Hamiltonian, which are determined by careful fitting of magnetic-field orientation-dependent ODMR spectra of in-plane aligned SWCNTs. While the triplet excitons only weakly depend on the nanotube environment, an increase in zero-field splitting is found for (6,5) with respect to (7,5) nanotubes, in good agreement with the tighter confinement expected in the narrower-diameter nanotubes.

[1] M.S. Dresselhaus et al, Ann. Rev. Phys. Chem. 2007, 58, 719

[2] D. Stich et al, Nature Photon.
2014
, 8,139; J. Palotás et al, ACS Nano 2020, 14, 11254
(Invited) Hybrid Interfaces between Semiconducting Swcnts and Other Low-Dimensional Semiconductors
Authors: Blackburn Jeff , Hao Ji , Kim Young-Hoon , Lu Haipeng , Luther Joey , Phillips Alan , Gish Melissa , Myers Alexis
Published: July 2022

Low-dimensional semiconductors provide a rich tapestry of tunable optical and electrical properties for a wide variety of applications. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have shown tremendous potential in applications ranging from digital logic, biological imaging, quantum information processing, photovoltaics, and thermoelectric energy harvesting. Energy harvesting applications rely critically upon the creation of tailored interfaces that enable the movement of energetic species (excitons, electrons, holes) in specified directions. While organic energy harvesting devices often employ interfaces between distinct organic species such as polymers, fullerenes, and carbon nanotubes, hybrid interfaces between organic and inorganic semiconductors have unique properties that are relatively unexplored.

In this talk, I will discuss our recent efforts at constructing novel hybrid interfaces between s-SWCNTs and other low-dimensional semiconductors, including monolayer transition metal dichalcogenides and metal-halide perovskites. I will discuss time-resolved spectroscopy results exploring photoinduced separation of (in some case spin-polarized) charges across such interfaces, demonstrating utility for photovoltaics and novel photodetectors. Complementary device studies demonstrate exceptional efficiencies for conversion of photons into stable photocurrent, and I will highlight several novel applications in which these interfaces can be employed.
(Invited) Bio-Templated Carbon Nanotube Electronics
Authors: Sun Wei , Zhao Mengyu , Ouyang Yifan , Chen Yahong , Zheng Ming , Zhu Zhi
Published: July 2022

Towards the ultra-scaled 3 nm technology node and beyond, carbon nanotube (CNT) has been projected as one potential substitute for the semiconducting Si, because of its small energy gaps, atomic precise interface, and high charge mobility. In particular, CNT arrays, precisely assembled on DNA templates, display uniformly prescribed inter-CNT pitches down to 10 nm, which balances the competing needs between high on-state performance and fast on/off switching. However, till now, the functionality of bio-templated CNT electronics has been limited to single transistor, with critical contact pitch of several hundred nanometers. It remains less explored to perform complex logic computations using the ultra-scaled bio-templated transistors. By wiring multiple individual CNT transistors into one device, we demonstrated performing Boolean logic gates within the bio-templated electronics. These bio-templated transistors could be further scaled to small physical dimensions, as well as implemented with fast on/off switching characteristics. Our works suggest the potentials of building complex energy-efficient circuits from the bio-templated assembly of CNTs.
Probing Charge Transport in Sp
3-Functionalized Single-Walled Carbon Nanotubes with Terahertz Spectroscopy
Authors: Zorn Nicolas Frederic , Zheng Wenhao , Wang Hai , Zaumseil Jana
Published: July 2022

The covalent functionalization of semiconducting single-walled carbon nanotubes (SWCNTs) with luminescent sp
3-hybridized defects gives rise to tunable, narrowband emission in the near-infrared and increases their photoluminescence quantum yields [ACS Nano
2019, 13, 9259]. To enable their application in electrically driven light sources, a detailed understanding of the impact of sp
3 defects on charge transport within individual nanotubes and nanotube networks is required. Here, we investigate the ultrafast carrier dynamics in sp
3-functionalized, polymer-sorted (6,5) SWCNT dispersions and thin films using optical-pump terahertz-probe (OPTP) spectroscopy. OPTP spectroscopy relies on the photo-generation of charge carriers that are subsequently probed by a single-cycle terahertz pulse, rendering it a highly suitable technique for the determination of intrinsic charge transport properties (e.g., carrier mobility) in a quantitative and contact-free fashion. We observe a large transient photoconductivity of pristine and functionalized nanotubes that is dominated by the contribution of free charge carriers. The photoconductivity intensity and lifetime decrease upon functionalization, corroborating the impact of sp
3 defects on intra-nanotube charge transport. Through combination of (temperature-dependent) OPTP measurements of sp
3-functionalized SWCNT dispersions and films with electrical measurements of ambipolar, light-emitting field-effect transistors based on functionalized SWCNT networks [ACS Nano
2021, 15, 10451], we can separate the contributions of sp
3 defects (intra-nanotube) and nanotube junctions (inter-nanotube) to charge transport in such networks and distinguish the short- and long-range transport characteristics.

Fig. 1: Ultrafast optical-pump terahertz-probe spectroscopy is a highly suitable technique to study the intrinsic charge transport properties of sp
3-functionalized (6,5) SWCNTs in dispersions and thin films.

Figure 1
(Invited, Digital Presentation) Global Alignment of Carbon Nanotubes Via High Precision Microfluidic Dead-End Filtration
Authors: Rust Christian , Li Han , Gordeev Georgy , Spari Manuel , Guttmann Markus , Jin Qihao , Reich Stephanie , Flavel Benjamin S
Published: July 2022

Single wall carbon nanotubes (SWCNTs) dispersed by negatively charged sodium deoxycholate (DOC) or positively charged cetrimonium bromide (CTAB) are shown to assemble into aligned films (3.8 cm²) on polycarbonate membranes by slow flow dead-end filtration. Global alignment (S2D max » 0.85) is obtained on both pristine polyvinylpyrrolidone (PVP) coated membranes and those with an intentional 150 nm – 600 nm groove pattern from hot-embossing. In all cases, a custom microfluidic setup capable of precise control and measurement of the volume rate, trans-membrane pressure and the filtration resistance is used to follow SWCNT film formation. Conditions associated with the formation of SWCNT crystallites or their global alignment are identified and these are discussed in terms of membrane fouling and the interaction potential between the surface of the membrane and nanotubes. SWCNT alignment is characterised by cross polarized microscopy, AFM, SEM and Raman spectroscopy.

https://doi.org/10.1002/adfm.202107411
(Digital Presentation) Thermoelectric and Electronic Transport Studies of Ultrahigh-Conductivity Aligned Carbon Nanotube Assemblies
Authors: Komatsu Natsumi , Marquez Peraca Nicolas , Ichinose Yota , Li Xinwei , Dewey Oliver S. , Taylor Lauren W. , Trafford Mitchell , Mojibpour Ali , Yomogida Yohei , Wehmeyer Geoff , Yanagi Kazuhiro , Pasquali Matteo , Foster Matthew , Kono Junichiro
Published: July 2022

Macroscopic assemblies of aligned carbon nanotubes (CNTs) have been doubling in conductivity every three years and have now surpassed 10 MS/m [1]. They are promising for replacing copper- or aluminum-based electrical cables in applications where flexibility or weight savings are critical considerations. Understanding of transport processes in these ordered CNT assemblies is critical towards further conductivity improvement; yet, fiber-level transport is still poorly understood. Here, we studied thermoelectric and electrical properties of aligned CNT fibers and bundles produced by solution spinning. We first measured thermoelectric properties while tuning the Fermi energy and demonstrated a giant thermoelectric power factor [2]. We then performed temperature- and magnetic field-dependent conductivity measurements. In contrast to the majority of transport studies of CNT networks [3,4], our aligned CNT fibers exhibited a metallic behavior in a wide temperature range (30-300 K), i.e., conductivity monotonically increasing with decreasing temperature, which we attribute to the excellent sample morphology. At temperatures below 30 K, we observed a gradual decrease of conductivity with decreasing temperature, together with negative magnetoresistance, consistent with the weak localization theory for disordered metals. We determined the dimensionality and coherence lengths of carriers via analysis of the weak localization behavior. In addition to macroscopic CNT fibers with diameters of ~10 μm, we also conducted conductivity measurements on individual crystalline CNT bundles (with diameters ~ 50 nm and lengths ~ 30 μm) that constitute the fibers.

References

[1] L. W. Taylor, O. S. Dewey, R. J. Headrick, N. Komatsu, N. M. Peraca, G. Wehmeyer, J. Kono, and M. Pasquali, Carbon N. Y. 171, 689 (2021).

[2] N. Komatsu, Y. Ichinose, O. S. Dewey, L. W. Taylor, M. A. Trafford, Y. Yomogida, G. Wehmeyer, M. Pasquali, K. Yanagi, and J. Kono, Nat. Commun. 12, 4931 (2021).

[3] W. Zhou, J. Vavro, C. Guthy, K. I. Winey, J. E. Fischer, L. M. Ericson, S. Ramesh, R. Saini, V. A. Davis, C. Kittrell, M. Pasquali, R. H. Hauge, and R. E. Smalley, J. Appl. Phys. 95, 649 (2004).

[4] N. F. Zorn and J. Zaumseil, Appl. Phys. Rev. 8, 41318 (2021).
Loss of sphingosine kinase 2 protects against cisplatin-induced kidney injury
Authors: Xie Dengpiao , Hu Gaizun , Chen Chaoling , Ahmadinejad Fereshteh , Wang Weili , Li Pin-Lan , Gewirtz David A. , Li Ningjun
Published: July 2022

The present study provides new findings that sphingosine kinase 2 (SphK2) is highly expressed in renal tubules, cisplatin treatment increases the expression of SphK2 in proximal tubular cells and kidneys, and inhibition of SphK2 alleviates cisplatin-induced kidney injury by suppressing the activation of NF-κB, production of inflammatory factors, and apoptosis. SphK2 may serve as a potential therapeutic target for the prevention or treatment of cisplatin-induced nephrotoxicity.
[Retracted] Effects of Vibration Training on Weight Loss and Heart Rate Variability in the Obese Female College Students
Authors: Deng Wei
Published: July 2022

Objective. The present study examined the effects of a 12‐week whole‐body vibration training (WBVT) regimen on heart rate variability (HRV) and body composition in the obese female college students. Methods. Participants were assigned to either the WBVT (n = 17) or obese control group (n = 19). The students in the WBVT group conducted a 12‐week (5 times per week and 30 min per time) exercise protocols (30 to 40 Hz of frequency and 4 mm of amplitude), and the obese control group did not perform regular physical training during 12 weeks of study. Then, body composition (body weight, BMI, body fat, body fat percentage; trunk fat mass, muscle mass, MM) and HRV (time domain and frequency domain index) were measured in all subjects before and after WBVT intervention. Results. (1) After 12‐week WBVT intervention, body fat mass, trunk fat mass, and body fat percentage significantly decreased and muscle mass increased in the WBVT group (P < 0.01, respectively); there was no significant change in body weight and BMI (P > 0.05, respectively). (2) After 12‐week WBVT intervention, LFn, LF/HF, and HR significantly decreased (P < 0.05, P < 0.01), R‐R interval and RMSSD significantly increased (P < 0.01, respectively), and there was no significant difference in HFn (P > 0.05). Nevertheless, there was no significant change before and after the test in body composition and HRV in the obese control group (P > 0.05, respectively). (3) After 12‐week WBVT intervention, compared with the obese control group, body fat mass, body fat percentage, trunk fat mass, and LF/HF significantly decreased (P < 0.05, P < 0.01), muscle mass, and RMSSD increased (P < 0.05) in the WBVT group; but there were no significant difference in other indicators (P > 0.05) between the obese control group and WBVT group. (4) The reduction of body fat percentage before and after the WBVT intervention are positively correlated with the reduction in the LFn and LF/HF (r = 0.542, r = 0.504; P < 0.05, respectively) and negatively correlated with the increase in the RMSSD (r = −0.514, P < 0.05), and the reduction of trunk fat mass are positively correlated with the reduction in the LF/HF (r = 0.540, P < 0.05). Conclusion. The results indicate that WBVT improves HRV and body composition in obese female college students, and the reduction in body fat percentage and trunk fat mass are associated with a shift in cardiac autonomic regulation towards vagal dominance and improve sympathetic‐vagus balance after WBVT intervention. In conclusion, WBVT may be a feasible treatment to improve cardiac autonomic function and body composition.
Research on Intelligent Control Engineering of Green Low-Carbon Buildings Based on Improved Trilateral Positioning Algorithm
Authors: Tu Ya
Published: July 2022

Industrial production, military applications, and environmental monitoring all require corresponding positioning functions as science and technology advance. The location information service has gradually grown in popularity. However, large-scale applications will consume a lot of energy and cause environmental issues. Our further development will therefore focus on how to maintain low-carbon development and advance green technology. The improvement of triangular location algorithm is used in this paper to realize the research of low-power Bluetooth indoor location using the intelligent control project of green low-carbon buildings as the research object. The results show that the improved algorithm significantly improves the accuracy. The daily monitoring of the elderly and the alarm processing in an emergency are experimentally practiced and analyzed through the research of low-power Bluetooth indoor location algorithm. The research on intelligent control engineering of green low-carbon buildings is realized.
Intravenous Immunoglobulin Inhibits Liver Cancer Progression by Promoting p38MAPK-Associated Apoptosis
Authors: Xu Fengjie , Lin Runzhui , Liu Jianrui , Chen Zeming , Zhuo Hua , Liu Xingmu
Published: July 2022

Objective. The aim of this study is to explore the effect of intravenous immunoglobulin (IVIG) on the development of rat hepatocellular carcinoma and its possible molecular mechanism. Methods. Sixty adult male Sprague-Dawley (SD) rats were randomly divided into three groups: control, diethylnitrosamine(DEN) + normal saline(NS), and DEN + IVIG groups, with 20 rats in each group. The  rats in the DEN + NS group and DEN + IVIG group were given DEN 0.2 g/kg intraperitoneal injection once on day 1 and then 0.05% DEN aqueous solution in drinking water to establish a rat liver cancer model. Immunoglobulin (IgG) was injected intraperitoneally into the DEN + IVIG group twice a week at the dose of 100 mg/kg, and saline was administered intraperitoneally into the control group at a 50 mg/kg dosage. The body weight of each group of rats was recorded twice a week. All treatments were maintained continuously for 12 weeks. After the intervention, the liver function indexes of rats were measured by a fully automated biochemical analysis instrument. The liver histopathology was observed by hematoxylin-eosin(HE) staining. Immunohistochemistry was used to detect c-myc protein expression, and Western blotting was used to determine p38MAPK and p-p38MAPK protein expressions, as well as apoptosis-related proteins such as Bcl-2, Bax, and cleaved caspase-3. Results. Compared with the rats in the DEN + NS group, rats in the DEN + IVIG group showed substantially higher body mass (P<0.05), higher survival rate (P<0.05), and lower liver function indexes (P<0.05). Few focal necrosis of cancer cells and few nuclear division were observed in the rats in the DEN + IVIG group. The rats in the DEN + NS group showed lamellar necrosis of cancer foci, destruction of normal liver lobular structure, and hepatocellular carcinoma cells. Immunohistochemical analysis results revealed that the expression of c-myc was reduced in the DEN + IVIG group (P<0.05), and Western blotting confirmed that the Bcl-2 expression was decreased (P<0.05), while Bax, p38 MAPK, p-p38 MAPK, and cleaved caspase-3 protein expressions were increased (P<0.05). Conclusion. IVIG prophylactic injection can delay tumor development and induce apoptosis in primary hepatocellular carcinoma in rats. The mechanism is connected to the activation of the p38MAPK signaling pathway by upregulating the level of cleaved caspase-3 and Bax proteins while downregulating the level of Bcl-2 and c-myc proteins.