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Articles 1 - 30 of 938
Full-Text Articles in Chemistry
Reduced Mediators Released By Cyanobacteria During Exoelectrogenesis Detected Using Differential Pulse Voltammetry, Laura T. Wey, Monica Brachi, Yagut Allahverdiyeva, Shelley D. Minteer
Reduced Mediators Released By Cyanobacteria During Exoelectrogenesis Detected Using Differential Pulse Voltammetry, Laura T. Wey, Monica Brachi, Yagut Allahverdiyeva, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Cyanobacteria generate electrical current through exoelectrogenesis (extracellular electron transfer) downstream of photosynthesis, yet the identity of the endogenous redox mediator(s) responsible remains unresolved. Here, we apply differential pulse voltammetry (DPV) to detect and characterise redox-active species released by Synechocystis sp. PCC 6803 under illumination. To enable sensitive detection, we developed an electrolyte intermediate between BG11 (Blue-Green-11) growth medium and MOPS (3-(N-morpholino)propanesulfonic acid) buffer that minimises background electrochemical interference while maintaining short-term cellular functionality. DPV revealed multiple light-enhanced oxidation peaks (0.1–0.65 V vs. saturated calomel electrode (SCE)) that were not resolvable using cyclic voltammetry, providing evidence that cyanobacteria release reduced compounds …
Microwave Spectrum And Iodine Nuclear Quadrupole Coupling Constants Of Difluorodiiodomethane, Cf2i2, Michael J. Carrillo, Michael J. Tubergen, Garry S. Grubbs, S. A. Cooke, Stewart E. Novick
Microwave Spectrum And Iodine Nuclear Quadrupole Coupling Constants Of Difluorodiiodomethane, Cf2i2, Michael J. Carrillo, Michael J. Tubergen, Garry S. Grubbs, S. A. Cooke, Stewart E. Novick
Chemistry Faculty Research & Creative Works
The high-resolution rotational spectrum of difluoro diiodomethane is reported for the first time. A molecular-beam broadband Fourier transform microwave spectrometer recorded the spectrum over the frequency range of 5.9–18.1 GHz. The rotational constants, centrifugal distortion constants, nuclear quadrupole coupling constants, and nuclear spin-rotation constants for the two equivalent iodine nuclei were determined from fitting 1378 hyperfine transitions of 163 rotational transitions: A = 2743.79691(18)MHz, B = 587.83103(5) MHz, C = 528.72470(5) MHz, χaa = −1213.287(6) MHz, χbb – χcc = −885.210(5) MHz, and χab = 1437.721(5) MHz. 31 dipole-forbidden/quadrupole-allowed transitions, arising from the large nuclear quadrupole coupling effect of iodine, …
“Innocent” Electrolytes Can Influence Organic Electrosynthetic Selectivity, Zachary A. Nguyen, Nhu H. Quach, Mayank Tanwar, Joshua A. Beeler, Kevin Mcfadden, Dylan G. Boucher, Matthew Neurock, Shelley D. Minteer
“Innocent” Electrolytes Can Influence Organic Electrosynthetic Selectivity, Zachary A. Nguyen, Nhu H. Quach, Mayank Tanwar, Joshua A. Beeler, Kevin Mcfadden, Dylan G. Boucher, Matthew Neurock, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Organic electrosynthesis has emerged as a powerful strategy for leveraging electricity in organic synthesis. Despite its growing popularity, the fundamental molecular interactions governing electrochemical systems remain poorly understood. Many electrosynthetic reactions show strong dependence on the identity of the allegedly inert supporting electrolyte, which can significantly impact yields and selectivity, yet the physical origins of these effects are largely unexplored. A mechanistic understanding of electrolyte effects would enable more rational reaction design for applications. Here, we use cyclic voltammetry to investigate cobalt-based metal–carbon bond homolysis and elucidate how common supporting electrolytes influence reaction rates. Bulk electrolysis experiments further reveal how …
An Automated Electrochemistry Platform For Accelerating The Characterization Of Enzymatic Electrochemistry, Michael A. Pence, Zachary A. Nguyen, Luke G. Kays, Dylan G. Boucher, Joaquín Rodríguez-López, Shelley D. Minteer
An Automated Electrochemistry Platform For Accelerating The Characterization Of Enzymatic Electrochemistry, Michael A. Pence, Zachary A. Nguyen, Luke G. Kays, Dylan G. Boucher, Joaquín Rodríguez-López, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Enzymatic electrochemistry harnesses the selectivity of enzymes to enable electrochemical applications spanning sensing, synthesis, and energy conversion. However, the sequential nature of electroanalytical experiments limits throughput, restricting the scale at which enzyme-electrode systems can be screened. Here we demonstrate the capabilities of an automated electrochemistry platform, eLab, to increase the throughput of enzymatic electrochemistry investigations. We used the eLab to collect over 10,000 cyclic voltammograms across a large parameter space consisting of two enzyme variants (promiscuous and wild-type glucose oxidase), 20 saccharide substrates, 21 concentrations, and four scan rates, with measurements being made all in triplicate. The expansive dataset enabled …
High-Throughput Optical Analysis To Inform Design Of Electrochemical Biosensors, Nathan J. Ricks, Michael A. Pence, Monica Brachi, Shelley D. Minteer
High-Throughput Optical Analysis To Inform Design Of Electrochemical Biosensors, Nathan J. Ricks, Michael A. Pence, Monica Brachi, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Electrochemical biosensors are central to wearable diagnostics, point-of-care testing, and continuous health monitoring due to their low power requirements, compatibility with miniaturized electronics, and proven clinical impact. Despite these advantages, the development of new electrochemical biosensors remains slow, constrained by limited throughput, complex electrode–biomolecule interfaces, and challenges associated with selectivity and performance in chemically complex environments. This perspective outlines how the next generation of electrochemical biosensors can be enabled by decoupling high-throughput front-end discovery and optimization from electrochemical readouts using nonelectrochemical surrogate assays. Optical, affinity, and cell-sorting platforms, including SELEX, fluorescence-activated cell sorting, and chemically coupled fluorescence assays, allow orders-of-magnitude …
Data-Driven Electrochemistry Reveals The Impact Of Hydrophobicity On Aptamer Cross-Reactivity, Emily Carroll, Michael A. Pence, Elizabeth Winterholler, Taylor D. Sparks, Shelley D. Minteer
Data-Driven Electrochemistry Reveals The Impact Of Hydrophobicity On Aptamer Cross-Reactivity, Emily Carroll, Michael A. Pence, Elizabeth Winterholler, Taylor D. Sparks, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Electrochemical aptamer-based (E-AB) biosensors offer a promising platform for reagentless detection of molecular targets, yet aptamer recognition can be limited by cross-reactivity, particularly for hydrophobic analytes such as steroid hormones. To investigate how cross-reactivity influences E-AB sensor performance, we use automation and machine learning to screen a library of possible interferent molecules against a steroid-binding aptamer, with progesterone serving as a physiologically relevant test case. Here, we develop a label-free E-AB sensor for progesterone detection using a methylene blue-modified aptamer anchored with a hexanethiol linker. We then used an automated electrochemistry platform to perform reproducible and high-throughput characterization of our …
Employing Ac And Dc Electrolysis To Modulate Electroenzymatic Pathways For Efficient And Stereoselective H-D Exchange, Wassim El Housseini, Rokas Gerulskis, Nibedita Behera, Huaijun Guan, Rohit G. Jadhav, Zachary A. Nguyen, Egor Baiarashov, Michael A. Pence, Vamshi Krishna Kamaja, Trevor Larkin, Long Luo, Shelley D. Minteer
Employing Ac And Dc Electrolysis To Modulate Electroenzymatic Pathways For Efficient And Stereoselective H-D Exchange, Wassim El Housseini, Rokas Gerulskis, Nibedita Behera, Huaijun Guan, Rohit G. Jadhav, Zachary A. Nguyen, Egor Baiarashov, Michael A. Pence, Vamshi Krishna Kamaja, Trevor Larkin, Long Luo, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
Stereoselective hydrogen isotope exchange (HIE) at chiral centers is an increasingly important strategy for preparing labeled molecules, yet its practical implementation depends on reliable control of nicotinamide cofactor regeneration. Here we introduce a redox-programmable electroenzymatic platform for stereoselective HIE based on electrode-controlled manipulation of the nicotinamide cofactor state. A wired ferredoxin–NADP+ reductase (FNR) electrode enables reversible electrochemical interconversion of NADP+ and its deuterated reduced form (NADPD) directly from D2O. Coupling this cofactor cycling with enantioselective alcohol dehydrogenases (ADHs) establishes a reversible alcohol–ketone redox manifold that drives efficient and stereoselective H-D exchange at chiral alcohols. Stereochemical outcomes are programmed …
Explicit Hydration Of The Beryllium Trifluoride Anion With One To Three Water Molecules: Bef3–(H2o)N=1–3, Kayleigh R. Autry, Gregory S. Tschumper
Explicit Hydration Of The Beryllium Trifluoride Anion With One To Three Water Molecules: Bef3–(H2o)N=1–3, Kayleigh R. Autry, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
This work investigates the micro hydration of the beryllium trifluoride anion (BeF3–) with up to three water molecules (BeF3–(H2O)n where n = 1–3). Full geometry optimizations and harmonic vibrational frequencies were computed on various BeF3–(H2O)n stationary points using density functional theory methods (B3LYP-D3BJ, B3LYP, ωB97XD, and M06-2X) as well as the CCSD(T) and MP2 ab initio methods with a triple-ζ correlation-consistent basis set augmented with diffuse functions on all non-hydrogen atoms (haTZ). One BeF3–(H2O)1, five BeF3– …
Probing Composition Effects On The Intrinsic Energetics Of Proton Transfer In Binary (Hcl)M(H2o)N Clusters, Max R. Tucker, Sarah N. Arradondo, Olivia M. Longsworth, George C. Shields, Gregory S. Tschumper
Probing Composition Effects On The Intrinsic Energetics Of Proton Transfer In Binary (Hcl)M(H2o)N Clusters, Max R. Tucker, Sarah N. Arradondo, Olivia M. Longsworth, George C. Shields, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
This work examines the effects on intrinsic energetics as the composition of finite (HCl)m(H2O)n cluster families containing at least one water molecule is changed at the molecular level, where m ≥ 2 and m + n = 4 − 6, and the associated (Cl−)x(H3O+)x(HCl)m−x(H2O)n−x clusters resulting from the dissociation of x HCl fragments via proton transfer (PT). They are collectively labeled m:n, and xPT indicates the degree of dissociation, from 0PT (no dissociation) up to 3PT. More than 1000 unique minima …
Uptake And Fate Of Silver And Zinc Engineered Nanoparticles In Maize Under Single And Binary Dosing Soil Ecosystems, Lei Xu, Qingbo Yang, Xingmao Ma, Honglan Shi, John Yang, Hu Yang, Samira Mahdi, Ying Wang, Young Shin Jun
Uptake And Fate Of Silver And Zinc Engineered Nanoparticles In Maize Under Single And Binary Dosing Soil Ecosystems, Lei Xu, Qingbo Yang, Xingmao Ma, Honglan Shi, John Yang, Hu Yang, Samira Mahdi, Ying Wang, Young Shin Jun
Chemistry Faculty Research & Creative Works
Recent agricultural applications of engineered metallic nanoparticles (ENPs) have raised concerns about their uptake and fate in plants. To understand this critical issue, this study investigated the fate and uptake of silver (Ag) and zinc oxide (ZnO) ENPs in maize (Zea mays L.) after single or binary ENP exposure in soil. Results indicated that both Zn and Ag elemental concentrations in roots increased with increasing ENP dosage. Ag NPs in the tissues were detected, but not Zn NPs. Ag NP concentration was 3 times higher in the roots than in the shoots at low Ag NP dosing, while Ag NP …
Quantum Scattering Of Hc5n And Para-H2 On A New Potential Energy Surface, Shan Gao, François Lique, Ernesto Quintas-Sánchez, Richard Dawes, Jérôme Loreau
Quantum Scattering Of Hc5n And Para-H2 On A New Potential Energy Surface, Shan Gao, François Lique, Ernesto Quintas-Sánchez, Richard Dawes, Jérôme Loreau
Chemistry Faculty Research & Creative Works
In the interstellar medium (ISM), non-local thermodynamic equilibrium situations are common due to low density, and one needs to consider the effect of molecular collisions in order to interpret the observations. Among the species detected in the ISM, cyanopolyynes, with the general molecular formula HC2n+1N (n = 1, 2, …), are characterized by large dipole moments and small rotational constants and constitute an indispensable class of candidates for the sensitive tracers of local density and temperature. We present a study of the collisional (de-) excitation of HC5N by para-H2 (p-H2) in its ground …
Electroenzymatic Cascades For Nitrogen Upgrading: Beyond Ammonia Towards Value-Added Nitrogen Chemicals, Rohit G. Jadhav, Vamshi Krishna Kamaja, Wassim El Housseini, Monica Brachi, Shelley D. Minteer
Electroenzymatic Cascades For Nitrogen Upgrading: Beyond Ammonia Towards Value-Added Nitrogen Chemicals, Rohit G. Jadhav, Vamshi Krishna Kamaja, Wassim El Housseini, Monica Brachi, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
The global transition toward sustainable chemical manufacturing demands technologies that leverage natural carbon and nitrogen cycles while minimizing reliance on sacrificial reagents and fossil resources. These biogeochemical cycles are fundamental to life, and enzymes catalyze many of their key transformations. Bio electrochemical, specifically electroenzymatic, systems offer a promising route to sustainable synthesis by enabling selective redox transformations powered by electricity. However, whereas carbon-cycle enzymes are now well established in bio electrochemical synthesis, enzymes from the nitrogen cycle remain comparatively underexplored. Moreover, the nitrogen cycle alone does not access many value-added nitrogen-containing products, which require additional C-N bond formation and organic …
Dendrimer Nanogels With Built-In Free Radical Scavenging Enable Efficient Topical Delivery Of A Hydrophilic Antioxidant To Restore Lens Redox Balance For Cataract Treatment, Lin Qi, Huari Kou, Anna Chernatynskaya, Da Huang, Vimalin Jeyalatha Mani, Humeyra Karacal, Nuran Ercal, Hu Yang
Dendrimer Nanogels With Built-In Free Radical Scavenging Enable Efficient Topical Delivery Of A Hydrophilic Antioxidant To Restore Lens Redox Balance For Cataract Treatment, Lin Qi, Huari Kou, Anna Chernatynskaya, Da Huang, Vimalin Jeyalatha Mani, Humeyra Karacal, Nuran Ercal, Hu Yang
Chemistry Faculty Research & Creative Works
Cataract is a leading cause of vision impairment worldwide and are primarily caused by oxidative stress that damages and aggregates lens proteins, leading to lens opacification. However, the eye's anatomical barriers limit the penetration and bioavailability of antioxidant therapies. To address this challenge, a dendrimer-based nanogel with a built-in reactive oxygen species (ROS)-scavenging capability developed by us was employed to deliver the antioxidant N-acetylcysteine (NAC) to the lens. NAC was loaded into a generation-5 PEGylated poly(amidoamine) dendrimer (G5-PEG-TK, termed the GPT) nanogel. The resulting NAC-GPT was characterized for its ROS-scavenging activity, bioavailability, and corneal permeability. The efficacy of NAC-GPT was …
Fluorescent Biosensor-Guided Engineering Of Enzyme Cascades For Electrochemical Applications, Nathan J. Ricks, Monica Brachi, Fnu Arun, Egor Baiarashov, Shelley D. Minteer, Ming C. Hammond
Fluorescent Biosensor-Guided Engineering Of Enzyme Cascades For Electrochemical Applications, Nathan J. Ricks, Monica Brachi, Fnu Arun, Egor Baiarashov, Shelley D. Minteer, Ming C. Hammond
Chemistry Faculty Research & Creative Works
Substrate channeling is a strategy for enhancing flux and yield in enzymatic cascades and is increasingly relevant for applications in biocatalysis, biotechnology, and bioelectrochemical systems. However, efforts to engineer channeling are limited by the lack of high-throughput methods to evaluate and optimize channeling efficiency. Here, we present a fluorescence-based screening assay to rapidly assess substrate channeling in a model system involving fumarase and malate dehydrogenase, two sequential enzymes from the Krebs cycle. By expressing genetic fusions in Escherichia coli, quantifying intermediate (malate) and product (NADH) formation in lysate using orthogonal fluorescent readouts, and comparing product-to-intermediate ratios, we screened a library …
Intramolecular Nonbonding Interactions And Geared Phenyl Twisting In Para-Disubstituted 1,4-Diphenylazines: Electron Correlation Effects On Molecular Conformations And Enantiomerization, Kaidi Yang, Harmeet Bhoday, Rainer Glaser
Intramolecular Nonbonding Interactions And Geared Phenyl Twisting In Para-Disubstituted 1,4-Diphenylazines: Electron Correlation Effects On Molecular Conformations And Enantiomerization, Kaidi Yang, Harmeet Bhoday, Rainer Glaser
Chemistry Faculty Research & Creative Works
The results are reported of potential energy surface (PES) analyses of six symmetrical azines Yp − Ph − RC=N − N=CR − Ph − Yp, namely, the benzaldehyde azines 1H, 2H, and 8H with R = H and the acetophenone azines 1M, 2M, and 8M with R = Me. The Y substituents Cl (1), Br (2), and Me (8) were studied because sets of polymorphs I (C2-symmetry, azine twist τ ≈ 135 ± 10°, disrotatory phenyl twists ϕi ≠ 0°) and II (Ci-symmetry, τ = 180°, conrotatory ϕi ≠ 0°) were crystallized for these three azines. The …
A Photosynthetic–Respiratory Electron Transport Chain Chimera Based On Photosystem I And Cytochrome C Oxidase On Graphene Oxide, Xiaoping Zhu, Matthew J. Kummer, Carolyn E. Lubner, Vasily Kurashov, William Carr, John H. Golbeck, Robert A. Niederman, Lev G. Mourokh, Shelley D. Minteer, Paul G. Falkowski, Michele Vittadello
A Photosynthetic–Respiratory Electron Transport Chain Chimera Based On Photosystem I And Cytochrome C Oxidase On Graphene Oxide, Xiaoping Zhu, Matthew J. Kummer, Carolyn E. Lubner, Vasily Kurashov, William Carr, John H. Golbeck, Robert A. Niederman, Lev G. Mourokh, Shelley D. Minteer, Paul G. Falkowski, Michele Vittadello
Chemistry Faculty Research & Creative Works
Te self-assembly of enzyme proteins on 2D nanomaterials has enabled the construction and functional control of viable biochemical pathways. However, enzymatic cascades, which combine essential components of the photosynthetic and respiratory electron transport chains in tandem, have thus-far remained elusive. Herein, we have investigated a galvanic biohybrid nano system coupling photosystem I and cytochrome c oxidase on the surface of graphene oxide nanosheets in colloidal suspension. Te oriented immobilization of the enzymes was facilitated by Ni-coordination sites tethered to the carbon basal plane, with negligible parasitic O2 consumption. Transient absorption and electrochemical measurements provided evidence of electron transfer between donors …
Long-Range Fit: A Software Package For The Representation And Study Of Long-Range Molecular Interactions, Adrian L. Batista-Planas, Ernesto Quintas-Sánchez, Richard Dawes
Long-Range Fit: A Software Package For The Representation And Study Of Long-Range Molecular Interactions, Adrian L. Batista-Planas, Ernesto Quintas-Sánchez, Richard Dawes
Chemistry Faculty Research & Creative Works
Describing intermolecular forces is fundamental to modeling and predicting the behavior of molecular systems. In particular, long-range molecular interactions with electrostatic, induction, and dispersion as the main components play a critical role, especially for low-temperature and low-density regimes. Long-range interactions are often described through perturbation theory, representing the electronic charge distribution via a multipolar series of the moments and polarizability tensors corresponding to each molecule. However, while the theory is well established, obtaining the resulting analytical expressions (and their practical implementation) constitutes a highly complex and system-dependent task. To address this challenge, we developed long-range-fit (LRF), an interactive and user-friendly …
Early Detection Of Infectious Diseases: A Review Of Recent Advances In Pathogen Identification, Molecular Tools, And Metabolomics-Driven Biomarker Discovery, Patrica Ivy Agorsor, Michael O. Eze
Early Detection Of Infectious Diseases: A Review Of Recent Advances In Pathogen Identification, Molecular Tools, And Metabolomics-Driven Biomarker Discovery, Patrica Ivy Agorsor, Michael O. Eze
Chemistry Faculty Research & Creative Works
The recent COVID-19 pandemic has heightened public interest in noninvasive methods for early diagnosis of infectious diseases. In addition, various government agencies have implemented "infectious disease preparedness" to mitigate future outbreaks. This review highlights conventional and advanced methods for infectious disease diagnosis with an emphasis on emerging mass spectrometry methods. Conventional methods for pathogen identification, such as culture-based techniques and molecular methods, have limitations with respect to sensitivity, specificity, and turnaround time. Recent advances in high-resolution mass spectrometry have revolutionized the field of infectious disease biomarker discovery. These techniques enable the comprehensive profiling of metabolites in various biological samples, identification …
Probing Proximal Intramolecular Hydrogen Bonding Interactions On A Norbornane Scaffold, Carly A. Rock, Dakota B. Green, Martin J. Flores, Jeremy M. Carr, Thufail M. Ismail, Gregory S. Tschumper
Probing Proximal Intramolecular Hydrogen Bonding Interactions On A Norbornane Scaffold, Carly A. Rock, Dakota B. Green, Martin J. Flores, Jeremy M. Carr, Thufail M. Ismail, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
A systematic computational study was conducted on 12 unique 2,6-disubstituted norbornane derivatives to assess the ability of various acceptor groups (A = F, Cl, Br, OH, OCH3, SH, SCH3, NHCH3, N(CH3)2, PH2, PHCH3, and P(CH3)2) to engage in intramolecular hydrogen bonding with a proximal OH donor. 32 unique minima have been characterized with M06-2X and df-MP2 geometry optimizations as well as PNO-LCCSD(T)-F12 single point energy computations. Conformations with the OH donor oriented toward the acceptor to form an OH···A contact (+HB) consistently had lower electronic energies (by approximately 2 to 8 kcal mol–1) than their counterparts with the …
Computational Characterization Of A Recently Identified Disinfection Byproduct In Drinking Water: The Chloronitramide Anion And Its Monohydrate Complex, Thufail M. Ismail, Max R. Tucker, Gregory S. Tschumper
Computational Characterization Of A Recently Identified Disinfection Byproduct In Drinking Water: The Chloronitramide Anion And Its Monohydrate Complex, Thufail M. Ismail, Max R. Tucker, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
The chloronitramide anion (ClNNO2−) was recently identified as disinfection byproduct in drinking water, and various quantum chemistry methods (CCSD(T), MP2, B3LYP, ωB97XD, and M06-2X) are employed in this study to characterize this negatively charged species and its monohydrate complex. Both vertical and adiabatic quantities indicate the excess electron is bound by 3–4 eV. Four ClNNO2− monohydrate minima were identified, each exhibiting double ionic hydrogen bonding. The computed ClNNO2−⋯H2O interaction approaches 15 kcal/mol, and it induces pronounced vibrational frequency shifts in both fragments. Natural bond orbital analysis shows a redistribution of …
Electric Dipole Forbidden, Quadrupole Allowed Transitions In The Pure Rotational Spectrum Of Cyclopropylchloromethyldifluorosilane, Alexander R. Davies, Abanob G. Hanna, Alma Lutas, Gamil A. Guirgis, S. A. Cooke, Garry S. Grubbs
Electric Dipole Forbidden, Quadrupole Allowed Transitions In The Pure Rotational Spectrum Of Cyclopropylchloromethyldifluorosilane, Alexander R. Davies, Abanob G. Hanna, Alma Lutas, Gamil A. Guirgis, S. A. Cooke, Garry S. Grubbs
Chemistry Faculty Research & Creative Works
In a recent publication, some electric dipole forbidden, quadrupole allowed ΔJ = +2 and x-type transitions were observed in the chirped-pulse Fourier transform microwave spectrum of two conformations of cyclopropylchloromethyldifluorosilane. Many of these transitions arise from a handful of mixed states and mechanisms are proposed through which these transitions become weakly allowed. Observations of electric dipole forbidden, quadrupole allowed transitions in rotational spectra are unusual for molecules which contain a chlorine nucleus owing to the small quadrupole moment of 35Cl and 37Cl; thus, we believe we are the first to observe x-type transitions arising from perturbations caused by …
Leveraging Molecular Mechanisms Of Desorption To Enhance Pfas Bioavailability In Contaminated Soils, Husam Kafeenah, Margaret D. Taiwo, Patrica Ivy Agorsor, Michael O. Eze
Leveraging Molecular Mechanisms Of Desorption To Enhance Pfas Bioavailability In Contaminated Soils, Husam Kafeenah, Margaret D. Taiwo, Patrica Ivy Agorsor, Michael O. Eze
Chemistry Faculty Research & Creative Works
Per- and polyfluoroalkyl substances (PFAS) are known for their strong binding properties to soil matrices owing to their amphiphilic properties. While most studies focus on the search for novel PFAS bio degraders, our knowledge of sustainable biomolecules that could drive PFAS desorption and make them more bioavailable is limited. This study investigated the effectiveness of rhamnolipids and organic acids in desorbing PFAS compounds from contaminated soil. Rhamnolipids (25 mg/L) significantly enhanced the release of PFAS compounds from soil, achieving up to 90 % desorption. Acetic acid provided 60–90 % desorption efficiency for most of the PFAS studied, except for PFDA …
Heterogeneous Catalysis Of Large Biomolecules: Insights From Platinum Particle Size In Nad+Regeneration, Jianwei Li, Samuel Robertshaw, Shouying Huang, Shelley D. Minteer, Xiaodong Wang
Heterogeneous Catalysis Of Large Biomolecules: Insights From Platinum Particle Size In Nad+Regeneration, Jianwei Li, Samuel Robertshaw, Shouying Huang, Shelley D. Minteer, Xiaodong Wang
Chemistry Faculty Research & Creative Works
Nicotinamide adenine dinucleotide (NAD+) cofactor regeneration is essential for enabling dehydrogenase-promoted biosynthesis for value-added chemicals. Heterogeneous catalytic cofactor regeneration, using supported metal catalysts, is an emerging approach and has shown great promise. However, mechanistic insight remains largely unexplored. In this work, a series of silica-supported platinum (Pt) catalysts have been prepared for NAD+ cofactor regeneration, to understand the roles of Pt particle size and structure. A turnover frequency (TOF) 'volcano plot' was obtained for Pt clusters in the range of 2.2–7.1 nm, with the maximum TOF (136 h−1) observed at 5.6 nm. Selective Pt site …
Ultrasonic Extraction-Based Analysis Of Persistent Organic Pollutants In Blubber From False Killer Whales, Michael O. Eze, Eva Borras, Mitchell M. Mccartney, Don R. Bergfelt, Kristi L. West, Sarah E. Hooper, Cristina E. Davis
Ultrasonic Extraction-Based Analysis Of Persistent Organic Pollutants In Blubber From False Killer Whales, Michael O. Eze, Eva Borras, Mitchell M. Mccartney, Don R. Bergfelt, Kristi L. West, Sarah E. Hooper, Cristina E. Davis
Chemistry Faculty Research & Creative Works
In view of the toxic effects of persistent organic pollutants (POPs), fast and effective assessment of their concentrations in marine mammals is important for understanding individual and population-level health impacts. This study developed an ultrasonic-based method that is less time-consuming, uses minimal solvent, and thus is more sustainable than the gold standard Soxhlet method for accurate analysis of organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and benzene hexachlorides (BHC) in false killer whale blubber. This method was developed by comparing concentrations of POPs obtained using the traditional Soxhlet and novel ultrasonic extraction methods using blubber from false killer whales (n = …
Synergistic V2ctₓ Mxene–Pani Hybrid With Expanded Interlayers For Ultrastable And High-Rate Pseudocapacitive Energy Storage, Amideddin Nouralishahi, Maryam Sharifi Paroushi, Mansour Razavi, Amarachi Clare Nnachor, Harish Singh, Manashi Nath
Synergistic V2ctₓ Mxene–Pani Hybrid With Expanded Interlayers For Ultrastable And High-Rate Pseudocapacitive Energy Storage, Amideddin Nouralishahi, Maryam Sharifi Paroushi, Mansour Razavi, Amarachi Clare Nnachor, Harish Singh, Manashi Nath
Chemistry Faculty Research & Creative Works
Recently, MXene-conducting polymer hybrids have emerged as promising electrode materials for sustainable energy storage applications, owing to their impressive electrochemical properties. Herein, we report the synthesis of vanadium carbide MXene nanoparticles (V2CTx-MXene) using innovative Spark Plasma Sintering (SPS) technology followed by exfoliation steps. The V2CTx nanoparticles were incorporated with PANI (MXene-PANI) by electrochemical polymerization of aniline monomers in the presence of V2CTx nanolayers, to be used as a highly efficient material for charge storage application. PANI nanofibers form a conductive and porous architecture, which intercalates the V2CTx nanoflakes. The resulting structure increases the interlayer spacing …
Enhanced Superconductivity And Vortex Dynamics In Quasi-1d Tas2 Nanowires, Mathew Pollard, Visakha Ho, Clarissa Wisner, Eric W. Bohannan, Yew San Hor
Enhanced Superconductivity And Vortex Dynamics In Quasi-1d Tas2 Nanowires, Mathew Pollard, Visakha Ho, Clarissa Wisner, Eric W. Bohannan, Yew San Hor
Chemistry Faculty Research & Creative Works
We report the synthesis of high-quality 2H-TaS2 nanowires via a controlled two-step conversion process from TaS3 precursors, achieving robust superconductivity with a transition temperature T c ≈ 3.6K, which is significantly higher than bulk 2H-TaS2 (T c ≈ 0.8K). Structural and compositional analyses confirm phase purity and preserved one-dimensional morphology, while magneto transport measurements reveal an enhanced upper critical field μ 0 H c2 (2K)≈5 T, far exceeding the bulk value (μ0Hc2 (0)≈1.17T), attributed to dimensional confinement and suppression of charge-density wave order. Magnetic characterization demonstrates complex vortex dynamics, including flux jumps and a …
Scalable Transfer Of Dna Origami–Directed Nanoparticle Arrays Onto Functional Surfaces Using Thermal Release Tape, Yuwei Zhang, Chikadibia Genevieve Edward, Ethan Keuhn, Shelley D. Minteer, Risheng Wang
Scalable Transfer Of Dna Origami–Directed Nanoparticle Arrays Onto Functional Surfaces Using Thermal Release Tape, Yuwei Zhang, Chikadibia Genevieve Edward, Ethan Keuhn, Shelley D. Minteer, Risheng Wang
Chemistry Faculty Research & Creative Works
Precise integration of DNA origami nanostructures onto functional substrates is essential for advancing electronics, photonics, and biosensing. However, most surface-assembly methods are highly sensitive to substrate type, limiting their broader applications. Here, we introduce a thermal release tape (TRT)-assisted transfer method that enables efficient, large-area printing of DNA origami-guided gold nanoparticle (AuNP-DNA origami) arrays from mica onto diverse surfaces. The method relies on differential adhesion: AuNP-DNA origami arrays form strong electrostatic and hydrogen-bonding interactions with 3-aminopropyltriethoxysilane (APTES)-functionalized receiver substrates, while the TRT adhesive weakens upon heating to 120°C, allowing release from the tape. Using this approach, well-ordered AuNP-DNA origami arrays …
Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For Conformance Control In Ultra-High Temperature Reservoirs, Yanbo Liu, Tao Song, Caleb Kwasi Darko, Thomas P. Schuman, Mingzhen Wei, Baojun Bai
Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For Conformance Control In Ultra-High Temperature Reservoirs, Yanbo Liu, Tao Song, Caleb Kwasi Darko, Thomas P. Schuman, Mingzhen Wei, Baojun Bai
Chemistry Faculty Research & Creative Works
Preferential fluid flow remains a major challenge in subsurface energy production and gas storage operations, resulting in excessive water production in mature oil fields, reduced heat extraction in geothermal reservoirs, and low sweep and storage efficiency in CO2-EOR projects. Polymer gels are widely used to mitigate high-permeability channels; however, conventional systems exhibit limited plugging efficiency and short lifetimes in ultra-high-temperature reservoirs due to poor thermal stability. This study presents a novel ultra-high-temperature-resistant preformed particle gel (UHT-PPG) developed for conformance control in reservoirs with temperatures of 150–275 °C and severe super-K or channeling problems. The material was evaluated in …
Progression Toward Terminal Oxidation Of Starch Via Hybrid Organic–Enzymatic Bioanode For Renewable Carbohydrate Conversion, Adam Milam, Jose Intano, Shelley D. Minteer
Progression Toward Terminal Oxidation Of Starch Via Hybrid Organic–Enzymatic Bioanode For Renewable Carbohydrate Conversion, Adam Milam, Jose Intano, Shelley D. Minteer
Chemistry Faculty Research & Creative Works
The performance of starch-based biofuel cells is fundamentally limited by inefficient utilization of the fuel's inherent energy density. Sequential oxidation of carbohydrate fuels, such as glucose, the monomeric unit of starch, using minimal catalyst systems has therefore emerged as a promising strategy to improve biofuel cell efficiency. Here, we extend a previously reported three-catalyst, organic–enzymatic glucose oxidation cascade to polymeric carbohydrate fuels by integrating enzymatic starch depolymerization with downstream electrochemical oxidation. To our knowledge, this represents the first demonstration of a defined hybrid organic–enzymatic cascade designed to drive progression of starch-derived glucose equivalents toward terminal oxidation using a minimal catalyst …
Concerted Proton Transfer In Homogeneous And Heterogeneous Cyclic Hydrogen-Bonded Clusters Of H2o, Hf, And Hcl, Max R. Tucker, Yuan Xue, Nathan R. Speake, Eden Nickolson, Jeremy M. Carr, Gregory S. Tschumper
Concerted Proton Transfer In Homogeneous And Heterogeneous Cyclic Hydrogen-Bonded Clusters Of H2o, Hf, And Hcl, Max R. Tucker, Yuan Xue, Nathan R. Speake, Eden Nickolson, Jeremy M. Carr, Gregory S. Tschumper
Chemistry Faculty Research & Creative Works
This work examines various homogeneous and heterogeneous clusters of hydrogen-bonded (HF)x(H2O)y(HCl)z complexes, where x + y + z = 3 or 4. For each unique cyclic structure associated with the xyz permutations, the geometries of the reactant, product, and transition state (TS) for concerted proton transfer (CPT) were fully optimized using second-order Møller-Plesset perturbation theory (MP2) with a mixed basis set consisting of cc-pVTZ for H atoms and aug-cc-pVTZ for O, Cl, and F atoms (denoted haTZ). Harmonic vibrational frequencies were also computed at the same level of theory to verify the nature of the stationary points. Intrinsic …