New Ideas From An Old Concept: The Hydrogen Bond,
2019
Utah State University
New Ideas From An Old Concept: The Hydrogen Bond, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Ongoing studies of the hydrogen bond (HB), in which a hydrogen (H) atom acts as a bridge between a pair of chemical groups, continues to offer new ideas about this interaction that have applications to biochemical processes. The ability of a proton to transfer within a HB can be controlled by conformational changes that cause small alterations to the HB geometry. The CH group, widely prevalent in biological systems, participates in HBs and contributes to the structure and stability of commonly occurring protein secondary structures such as the β-sheet. The concept of the HB has been extended to systems where …
Investigating Soluble Organic Compounds In Aqueously Altered Carbonaceous Chondrites By Ultrahigh Resolution Orbitrap Mass Spectrometry,
2019
Boise State University
Investigating Soluble Organic Compounds In Aqueously Altered Carbonaceous Chondrites By Ultrahigh Resolution Orbitrap Mass Spectrometry, Patrick Kyle Schwartz
Boise State University Theses and Dissertations
Most meteorites are fragments from main-belt asteroids and contain extremely primitive materials that have preserved a compositional record of the early Solar System. After the formation of their parent bodies, carbonaceous chondrites experienced secondary modification from thermal metamorphism and/or aqueous alteration. Secondary processing likely influenced the synthesis and/or final composition of organic compounds in parent bodies; thus, these effects may be elucidated from the study of different meteorites. Although the role of aqueous alteration has been investigated for a few specific classes of compounds (such as amino acids), the effect of aqueous alteration on the full inventory of organic compounds …
Monitoring Tropospheric Gases With Small Unmanned Aerial Systems (Suas) During The Second Cloudmap Flight Campaign,
2019
University of Kentucky
Monitoring Tropospheric Gases With Small Unmanned Aerial Systems (Suas) During The Second Cloudmap Flight Campaign, Travis J. Schuyler, Sean C. C. Bailey, Marcelo I. Guzman
Chemistry Faculty Publications
Small unmanned aerial systems (sUAS) are a promising technology for atmospheric monitoring of trace atmospheric gases. While sUAS can be navigated to provide information with higher spatiotemporal resolution than tethered balloons, they can also bridge the gap between the regions of the atmospheric boundary layer (ABL) sampled by ground stations and manned aircraft. Additionally, sUAS can be effectively employed in the petroleum industry, e.g., to constrain leaking regions of hydrocarbons from long gasoducts. Herein, sUAS are demonstrated to be a valuable technology for studying the concentration of important trace tropospheric gases in the ABL. The successful detection and quantification of …
Electrodeposition Of Hydrogen Molybdenum Bronze Films And Electrochemical Reduction Of Carbon Dioxide At Low Over Potentials,
2019
East Tennessee State University
Electrodeposition Of Hydrogen Molybdenum Bronze Films And Electrochemical Reduction Of Carbon Dioxide At Low Over Potentials, Sami Alharbi
Electronic Theses and Dissertations
Hydrogen molybdenum oxide, known has molybdenum bronze, is a material of interest due to catalyzing electron transfer reactions. Specifically, molybdenum bronze is an electrocatalyst toward carbon dioxide reduction. Electrochemical deposition from a peroxymolybdic acid solution is a method for preparing molybdenum bronze films. This work demonstrates reproducible electrodeposition on indium tin oxide substrates and conductive carbon paper. Film thickness depends on concentration, time and pH. After characterization by film thickness, resistance, XRD and XPS, the as deposited films served as the working electrode for electrochemical reduction of carbon dioxide in 0.1 M NaHCO3. Ion chromatography determined formate resulting …
Modification Of Chemical Vapor-Deposited Carbon Electrodes With Electrocatalytic Metal Nanoparticles Through A Soft Nitriding Technique,
2019
East Tennessee State University
Modification Of Chemical Vapor-Deposited Carbon Electrodes With Electrocatalytic Metal Nanoparticles Through A Soft Nitriding Technique, Enoch Amoah
Electronic Theses and Dissertations
Metal nanoparticles have been widely used for many catalytic and electrocatalytic applications due to their larger surface area-to-volume ratios and higher densities of active sites compared to bulk materials. This has resulted in much interest in understanding the electrocatalytic behavior of metal nanoparticles with respect to their structure. However, most research on this topic has employed collections of nanoparticles. Due to difficulties in controlling and characterizing particle loading and interparticle distance in nanoparticle ensembles, single nanoparticles studies have recently become a topic of great interest. In this study, a soft nitriding technique was applied to chemical vapor-deposited carbon ultramicroelectrodes (UMEs) …
Peroxide Sensing Using Nitrogen-Doped And Platinum Nanoparticle-Modified Screen-Printed Carbon Electrodes,
2019
East Tennessee State University
Peroxide Sensing Using Nitrogen-Doped And Platinum Nanoparticle-Modified Screen-Printed Carbon Electrodes, Chidiebere Ogbu
Electronic Theses and Dissertations
Nitrogen-doped carbon materials have garnered much interest due to their abilities to behave as electrocatalysts for reactions important in energy production (oxygen reduction) and biosensing (hydrogen peroxide reduction). Here, we demonstrate fabrication methods and determine electrocatalytic properties of nitrogen-doped screen-printed carbon (N-SPCE) electrodes. Nitrogen doping of graphite was achieved through a simple soft-nitriding technique which was then used in lab-formulated screen-printing inks to prepare N-SPCEs. N-SPCEs displayed good electrocatalytic activity, reproducibility and long term stability towards the electrochemical reduction of hydrogen peroxide. N-SPCEs exhibited a wide linear range (20 µM to 5.3 mM), reasonable limit of detection of 2.5 µM, …
Immobilization Of Electrocatalytically Active Gold Nanoparticles On Nitrogen-Doped Carbon Fiber Electrodes,
2019
East Tennessee State University
Immobilization Of Electrocatalytically Active Gold Nanoparticles On Nitrogen-Doped Carbon Fiber Electrodes, Daniel Mawudoku
Electronic Theses and Dissertations
Studies of single, isolated nanoparticles provide better understanding of the structure-function relationship of nanoparticles since they avoid complications like interparticle distance and nanoparticle loading that are typically associated with collections of nanoparticles distributed on electrode supports. However, interpretation of results obtained from single nanoparticle immobilization studies can be difficult to interpret since the underlying nanoelectrode platform can contribute to the measured current, or the immobilization technique can adversely affect electron transfer. Here, we immobilized ligand-free gold nanoparticles on relatively electrocatalytically inert nitrogen-doped carbon ultramicroelectrodes that were prepared via a soft nitriding method. Sizes of the particles were estimated by a …
Quality Of Wheat Grains (Triticum Aestivum) Generationally Exposed To Cerium Oxide Nanoparticles (Nceo2),
2019
Missouri State University
Quality Of Wheat Grains (Triticum Aestivum) Generationally Exposed To Cerium Oxide Nanoparticles (Nceo2), Oluwasegun Michael Abolade
Graduate Theses/Dissertations
The impacts of generational exposure to engineered nanomaterial on grain quality are poorly documented. This study was performed on wheat grains harvested from plants grown in soil amended with cerium oxide nanoparticles (nCeO2) at the 2nd and 3rd generations. Third generation experiment was performed at low and high nitrogen (N) soil levels. The goal was to investigate changes in grain fatty acid and elemental contents due to parental exposure (C1 vs T1 in 2nd generation, C1C2 vs T1T2 in 3rd generation) or current generation …
Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications,
2019
University of Arkansas, Fayetteville
Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications, Md Foysal Zahid Khan
Graduate Theses and Dissertations
In this work, a novel microfluidic pumping approach, redox-magnetohydrodynamics (R-MHD) has improved by materials and device optimization to use in lab-on-a-chip applications. In R-MHD, magnetic flux (B) and ionic current density (j) interacts to generate body force (FB) in between active electrodes, according to the equation FB = j×B. This unique fluid pumping approach is scalable, tunable, generates flat flow profile, and does not require any channels or valves. Pumping performance, such as speed scales with the ionic current density (j) and duration depends on the total charge (Q). The ionic current density (j) results from the conversion of electronic …
Modified Ambient Mass Spectrometric Methods For Field Screening And Confirmation Of Forensic Evidence,
2019
Illinois State University
Modified Ambient Mass Spectrometric Methods For Field Screening And Confirmation Of Forensic Evidence, William Lee Fatigante
Theses and Dissertations
The utility of field-portable analytical instrumentation has the potential to revolutionize many fields of science, particularly for forensic science and law enforcement. While colorimetric testing can be employed for drug evidence screening, the influx of novel psychoactive substances has significantly decreased the effectiveness of this investigation strategy. One approach to meeting the needs of today’s practitioner is coupling flexible, ambient ionization techniques with portable mass spectrometric (MS) instrumentation. Ambient ionization techniques have a rich history of being amendable to the sample at hand. Since their inception in 2005, numerous techniques saturate the field. The main drive for this development is …
Potential For On-Site, Prosecutorial Evidence From Drug Residues Collected On Plasmonic Paper: A Pilot Study For Sers-Psi-Ms,
2019
Illinois State University
Potential For On-Site, Prosecutorial Evidence From Drug Residues Collected On Plasmonic Paper: A Pilot Study For Sers-Psi-Ms, Daniel S. Burr
Theses and Dissertations
Given the potential impact of improvements to on-site drug testing, as well as recent, successful displays of paper spray ionization mass spectrometry (PSI-MS) in this regard, this thesis pilots the implementation of Raman spectroscopy as a compliment to MS for field-based confirmatory drug testing. Surface enhanced Raman scattering (SERS) is utilized for applications to trace detection. Two-tiered analysis of individual drug samples is enabled using triangularly-cut plasmonic papers, from which both SERS and PS-MS analysis may be performed. Several drug compounds, representative of traditional and emerging drug types, are examined by these techniques, both separately and as a fully integrated, …
Electropolymerization And Characterization Of Thin Film Dielectrics,
2019
University of Nebraska-Lincoln
Electropolymerization And Characterization Of Thin Film Dielectrics, Christopher White Ii
Department of Chemistry: Dissertations, Theses, and Student Research
Graphene is a two-dimensional allotrope of carbon, with several superlative properties, including high electron and hole conductivities, high tensile strength, and chemical robustness. Its chemical and physical properties make it attractive for in use in a myriad of applications, including transistors. However, graphene’s chemical inertness and its physical and electrical properties’ dependency on its conjugated structure make building composite materials with graphene difficult. In 2015, Lipatov, et. al. demonstrated that a film derived from electropolymerized phenol could be used as a dielectric layer on transistor devices fabricated from exfoliated graphene. This thesis extends that research, detailing experiments of phenol and …
Recent Advances In Nanofluidic Electrochemistry For Biochemical Analysis,
2019
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China;
Recent Advances In Nanofluidic Electrochemistry For Biochemical Analysis, Zhong-Qiu Li, Zeng-Qiang Wu, Xing-Hua Xia
Journal of Electrochemistry
Nanofluidics, as a young research field, has been receiving more and more attentions. It has been successfully applied in various fields including nanoscale separation, biochemical sensing and energy conversion. The development of nanofluidics is closely related to electrochemistry that can provide a driving force for the study of the material transport characteristics in nanopores/nanochannels. On the other hand, nanopores/nanochannels can creat a microenvironment for study of spatially nanoconfined electrochemistry. The combination of nanofluidics and electrochemistry has given rise to many new theories and technologies for single molecule/particle analysis and nanofluid manipulation. Herein, we provide a review of the recent progresses …
Study On The Relationship Between Structure Of Supramolecular Ion Material And Performance Of Humidity Sensing,
2019
1. Key Laboratory of Environmental Friendly Chemistry and Applications of Ministry of Education,;
College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China; 2. Beijing National;
Study On The Relationship Between Structure Of Supramolecular Ion Material And Performance Of Humidity Sensing, Hui-Min Tang, Hai-Long Yan, Li Zhang, Jun-Jie Fei, Ping Yu, Lan-Qun Mao
Journal of Electrochemistry
Humidity measurement and control is one of the most notable issues in various areas, such as climate, industry,
agriculture, electronics, especially human comfort and health. In our previous study, we have found that a new kind of supramolecular
ionic material (SIM), consisting of an imidazolium-based dication (e.g., 1,10-bis(3-methylimidazolium-1-yl) decane, C10(mim)2) and
electroactive dianionic (e.g., 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS), shows ultrasensitive and ultrafast
response towards humidity sensing. Herein we prepared six kinds of imidazolium-based dications with different carbon chain
lengths (i.e., C4, C6, C8, C10, C12, C …
Electrochemical Biosensors For Wastewater-Based Epidemiology,
2019
School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom;
Electrochemical Biosensors For Wastewater-Based Epidemiology, Yu-Wei Pan, Kang Mao, Franziska Tuerk, Zhu-Gen Yang
Journal of Electrochemistry
Wastewater-based epidemiology (WBE) has been shown to be an innovative approach for evaluation of drug use trends and public health assessment by quantifying drug residues and/or metabolites (so-called biomarkers) in wastewater collected in a local treatment plant. Community sewage sensors have been proposed and demonstrated to be powerful tools for the analysis of sewage biomarkers. In particular, electrochemical biosensors have emerged as a rapid method for the analysis of biomarkers and pathogens in wastewater due to low cost, minimal sample processing and the ability to test in the field. It has been widely used for biomedical diagnosis, environmental monitoring and …
A Low Noise Temperature Control System For Nanopore-Based Single Molecule Analysis,
2019
1. School of Chemistry & Molecular Engineering, East China University of Science and Technology,;
A Low Noise Temperature Control System For Nanopore-Based Single Molecule Analysis, Cheng-Yu Yang, Zhen Gu, Zheng-Li Hu, Yi-Lun Ying, Yi-Tao Long
Journal of Electrochemistry
Nanopore employs a single bio-molecule interface, which is a highly sensitive single-molecule detection technology for measuring single biomolecules such as DNA, RNA, protein, and peptide. The interaction between single molecule and nanopore is thermodynamically controlled. Therefore, it is urgent to precisely control the temperature of the nanopore system without introduction of any noise. In this paper, we have developed a low-noise temperature control system for single-molecule detection of nanopores to achieve precise regulation at the ambient temperature during measurements. The system utilizes the thermoelectric effect of the semiconductor refrigerating chip to heat or cool the detection chamber, while adopts electromagnetically …
Single Particle Impact Electrochemistry: Analyses Of Nanoparticles And Biomolecules,
2019
Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China;
Single Particle Impact Electrochemistry: Analyses Of Nanoparticles And Biomolecules, Jian-Hua Zhang, Yi-Ge Zhou
Journal of Electrochemistry
Single particle impact electrochemistry (SPIEC) has grown rapidly in recent years and shown great promise in the analysis of nanoparticle properties as well as the detection of biomolecules including DNA, RNA, protein, enzyme, bacteria, virus, vesicles and others. This minireview summarizes recent advances in electroanalytical applications of SPIEC according to different analytical methods, i.e., direct electrolysis of nanoparticles or labeled nanoparticles, direct electrolysis of soft particles encapsulated redox molecule, indirect electrochemistry of particles, area and diffusion blocking, and changes in current magnitude and collision frequency.
Cysteine And Cystamine Co-Self-Assembled Monolayers For In Vivo Detection Of Ascorbic Acid,
2019
Department of Chemistry, Renmin University of China, Beijing 100872, China;
Cysteine And Cystamine Co-Self-Assembled Monolayers For In Vivo Detection Of Ascorbic Acid, Yue Zhang, Tao-Tao Feng, Wen-Liang Ji, Mei-Ning Zhang
Journal of Electrochemistry
Self-assembled monolayers (SAMs), which form highly ordered monolayers on the electrode surface through the gold-suffer bond, have attracted much attention in recent years. This stable layer not only can regulate the wettable properties of surface, but also can act as a promoter towards redox-active molecules. Here, we developed a simple and effective method to construct cysteine and cystamine co-self-assembled monolayer on gold microelectrode for in vivo detection of ascorbic acid (AA). The molar ratio at 1:1 of mixed monolayer has been found the optimum to enhance the electron-transfer kinetics of AA oxidation at low potential (ca. 0.10 V), meanwhile, it …
Current Statuses And Challenges Of Wearable, Flexible Electronic Sensors And Energy Storage Devices,
2019
Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, Guangdong, P. R. China;
Current Statuses And Challenges Of Wearable, Flexible Electronic Sensors And Energy Storage Devices, Zhong-Qian Song, Fang-Jie Han, Hui-Jun Kong, Jia-Nan Xu, Yu Bao, Dong-Xue Han, Li Niu
Journal of Electrochemistry
With the developments in the internet of things, artificial intelligence and human-computer interaction technology, soft, flexible and wearable electronic devices provide a novel platform for monitoring of the human vital signs, and recognition of human behaviors to connect human being and machine without consciousness. Recent progresses about wearable and flexible electronics that can provide accurate, non-invasive, long-term and continuous monitoring of human vital sings including pulse, temperature, skin activities, breathing and heart rate are summarized. The working mechanisms, current statuses and challenges in temperature sensor, strain sensor and pressure sensor are discussed. The review concludes with a prospect of current …
In Vitro Evaluation Of Ovarian Cancer Tumorigenesis As A Function Of Quinone Oxidoreducatse-1 And Cell Phenotype,
2019
Louisiana State University and Agricultural and Mechanical College
In Vitro Evaluation Of Ovarian Cancer Tumorigenesis As A Function Of Quinone Oxidoreducatse-1 And Cell Phenotype, Milcah S. Jackson
LSU Doctoral Dissertations
In vitro multicellular spheroids are attractive model systems for assessing genetic and epigenetic changes that occur in diseased tissues. Understanding how such alterations in gene and subsequent protein expression affect disease progression and metastasis, drug resistance, and recurrence is of great interest in cancer research. In this regard, examining expression and activity of proteins, such as those with cytoprotective ability that are overexpressed in cancer cells, in addition to cell phenotype (i.e., stem-like, epithelial, mesenchymal, or mixed), are two ways to evaluate genetic and epigenetic changes. Moreover, determining the impact that cytoprotective proteins and cell phenotype have on tumor formation …
