Chemistry Commons^™

Deposition Of Nickel/Iron Oxide Co-Catalysts Onto Titanium Dioxide Towards Water Photolysis, Md Towhidul Islam Tareqe

Masters Theses & Specialist Projects

Photocatalytic water splitting is one potential approach for sustainable hydrogen production, offering an environmentally friendly alternative to fossil fuels. This process typically employs metal–semiconductor hybrid systems, where the semiconductor absorbs sunlight to generate charge carriers, and the metal cocatalyst facilitates charge separation and surface redox reactions. Titanium dioxide (TiO₂) is a widely studied semiconductor due to its stability and abundance, but its limited absorption of the solar spectrum requires the incorporation of efficient cocatalysts. Platinum is regarded as the benchmark cocatalyst due to strong proton binding energy that easily facilitates the reduction of water to produce hydrogen gas. …

The Development Of High Throughput Assays For Identification And Evaluation Of Small Molecule Modulators Of The Pri-Microrna-18a—Hnrnp A1 Interaction, Emile N. Van Meter

Dissertations

Therapeutics targeting RNA is a rapidly growing field. While only 1.5% of the human genome encodes genes for protein, over 70% o=f the human genome contains the genes for noncoding RNAs that regulate protein expression and function. Expanding the paradigm of small molecule drug discovery from traditional protein targets to include RNA would broaden the therapeutic landscape and provide new methods to modulate previously undruggable targets. miRNAs (miRs) have been found to be aberrantly expressed in many disease states, including neurodegenerative diseases and cancers making them promising therapeutic targets. The production of functional, mature miRs requires multiple proteins in a …

Yizhi Sun: Profile Of The Newest Chbc Faculty Member., Danna Jaimes-Fajardo, Jeremy J. Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

Presents the research profile of Yizhi Sun, Assistant Professor, Chemistry and Biochemistry department. It highlights his research interests, education, and impact of his research.

Electrochemical And Electrocatalytic Properties Of Screen-Printable Carbon Inks Featuring Pyridinic Nitrogen-Containing Polymeric Binder, Albert Sam Junior

Electronic Theses and Dissertations

Screen-printable conductive inks have been widely applied to prepare electrodes for electrochemical sensing. These inks generally consist of conductive metal or carbon particles, solvents, and polymeric binders. Low-cost, carbon-based, screen-printable conductive inks are especially popular. However, screen-printed carbon electrodes (SPCEs) must often be modified after they are printed to impart the necessary characteristics (e.g., sensitivity, selectivity, stability) for the desired application. For example, nitrogen-doping of SPCEs, especially in ways that introduce pyridinic or pyrrolic nitrogen species, can impart electrocatalytic properties towards reduction of O₂, H₂O₂, and CO₂. While our previous work done …

Comparative Nitrene-Transfer Chemistry To Olefins Mediated By First-Row Transition Metal Catalysts Supported By A Pyridinophane Macrocycle With N4 Ligation, Himanshu Bhatia, Lillian P. Adams, Ingrid Cordsiemon, Suraj Kumar Sahoo, Amitava Choudhury, Thomas R. Cundari, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

A 12-membered pyridinophane scaffold containing two pyridine and two tertiary amine residues is examined as a prototype ligand (^tBuN4) for supporting nitrene transfer to olefins. The known [(^tBuN4)M^II(MeCN)2]²⁺ (M = Mn, Fe, Co, and Ni) and [(^tBuN4)Cu^I(MeCN)]⁺ cations are synthesized with the hexafluorophosphate counteranion. The aziridination of para-substituted styrenes with PhI=NTs (Ts = tosyl) in various solvents proved to be high yielding for the Cu(I) and Cu(II) reagents, in contrast to the modest efficacy of all other metals. For α-substituted styrenes, aziridination is accompanied by products of aziridine …

Comparative Expression Of Cgmp-Dependent Protein Kinase G (Pkg) From Plasmodium And Toxoplasma, Tsopmo Asaah

Theses, Dissertations and Culminating Projects

Malaria and Toxoplasmosis are life threatening diseases to humans. The search for a cure and control of these diseases is still one of the major challenges of scientists worldwide. In this research we focused on two Malaria species; Plasmodium bergei² (Pb) and Plasmodium falciparum¹ (Pf) and also on Toxoplasma gondii. Part of the life cycle of these organisms is regulated by the enzyme cyclic GMP-dependent protein kinase G (PKG)⁴. This is our drug target in this research. We believe that inhibiting this enzyme will be a great step in fighting these diseases. In this research, we devised a comparative study …

Investigating The Influence Of Experimental Parameters On The Formation Of Gold Nanoparticles: A Green Synthesis And Design Of Experiments Approach, Isaac Opeyemi Subuloye

Master's Theses

This thesis examines the green synthesis of gold nanoparticles using catechin, a naturally occurring plant-derived compound, as both a reducing and capping agent. The synthesis process was guided by a structured Design of Experiments (DOE) methodology to ensure systematic investigation and optimization. A two-phase experimental approach was adopted. First, a full factorial screening design was used to evaluate the effects of catechin concentration, NaOH concentration, and pre-reaction time. This was followed by an optimization phase using a face-centered composite design to identify conditions that produce nanoparticles with ideal characteristics. The nanoparticles were analyzed using UV-visible spectroscopy and dynamic light scattering …

Visceral, Neural, And Immunotoxicity Of Per- And Polyfluoroalkyl Substances: A Mini Review, Pietro Martano, Samira Mahdi, Tong Zhou, Yasmin Barazandegan, Rebecca Iha, Hannah Do, Joel Burken, Paul Ki-Souk Nam, Qingbo Yang, Ruipu Mu

Chemistry Faculty Research & Creative Works

Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, such as inhalation and dermal absorption, also play a significant role. This review provides a concise overview of the toxicological impacts of both legacy and emerging PFASs, such as GenX and perfluoro butane sulfonic acid (PFBS), with a particular focus on their effects on the liver, kidneys, and immune and nervous systems, based on findings from recent …

Progress Towards Uranium Isotope Ratio Measurements Directly From Cotton Swipes With The Liquid Sampling – Atmospheric Pressure Glow Discharge (Ls-Apgd) Ionization Source, Joseph V. Goodwin

All Dissertations

The liquid sampling – atmospheric pressure glow discharge (LS-APGD) ionization source is a novel microplasma ionization source capable of ionizing a diverse set of both inorganic and organic chemical species including, ionic metal constituents as well as ligated metallic species, polyaromatic hydrocarbons (PAH), halogens, proteins, and even per/poly fluorinated alkyl substances (PFAS). The ability to generate ions from diverse chemical species, known as combined atomic and molecular (CAM) ionization, is not found with traditional ionization sources. In addition, the LS-APGD is capable of coupling with mass spectrometer platforms typically reserved for “organic” mass spectrometry, such as the high-resolution Orbitrap mass …

Reductive And Nucleophilic Cleavage Of Peroxides And Synthesis Of Tocotrienols As Radioprotective Targets, Amber Marie Schuster

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

I. SET CLEAVAGE OF PEROXIDES: INFLUENCE OF REDUCTANT AND PEROXIDE ON THE RATE AND MODE OF ALKOXY RADICAL FORMATION

The reductive cleavage of organic peroxides to generate alkoxy radicals is frequently accomplished via single-electron transfer (SET) from a reductant. Previous reports employ either symmetrical peroxides or peroxides with predictable cleavage behavior, such as peresters. We were interested in how the structure of the peroxide and the nature of the reducing system combine to impact the rate of reaction and the selectivity for alkoxy radical formation during cleavage of unsymmetric peroxides. In this dissertation, one will find the reactions of a …

Aptamer Selection And Development Of Electrochemical Aptamer-Based Sensors For Neuropeptide Y, Evelyn Adela Carreto Guevara

Department of Chemistry: Dissertations, Theses, and Student Research

In this thesis, we report the results of four aptamers obtained from an aptamer selection process called the systematic evolution of ligands by exponential enrichment (SELEX) with affinity to Neuropeptide Y (NPY). NPY is a highly abundant peptide transmitter with widespread distribution throughout the body which affects various physiological functions. These functions include energy homeostasis, appetite regulation, stress response, and anxiety regulation. Dynamic monitoring of NPY levels is crucial for better understanding behaviors in individuals with neurological disorders associated with NPY. Aptamers are synthetic oligonucleotides obtained through SELEX which have a binding affinity to a target of interest when in …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Recent Studies On The Reactions And Synthesis Of Nitrogen And Sulfur - Containing Heterocyclic Pharmacophores., Bernard Louis Adjei

Electronic Theses and Dissertations

Nitrogen and sulfur-containing heterocycles remain significant classes of compounds in the field of medicinal and organic chemistry due to their unique structural features and diverse biological activities which make them of considerable interest for drug discovery and development. Notable examples of the nitrogen containing heterocycles include the phthalimide and glutarimide rings present in thalidomide. Thalidomide, a potent small-molecule therapeutic agent, precipitated a significant global drug crisis due to its teratogenicity, causing congenital malformations in phocomelia infants, which remains unrivaled over half a century ago. Currently, thalidomide derivatives are extensively utilized in the therapeutic management of various hematological malignancies. Recent investigations …

Synthetic And Pharmacological Diversity Of Nitrogen-Containing Heterocycles., Shramana Ghosh

Electronic Theses and Dissertations

Nitrogen-containing heterocycles are a foundational class of compounds in organic chemistry, playing critical roles in pharmaceuticals, agrochemicals, and natural products due to their structural diversity and biological relevance. Among them, isoindolinones are notable for their wide range of pharmacological activities. Structurally, isoindolinones possess a benzylic methylene group adjacent to the nitrogen atom, which allows for selective oxidative transformations to yield phthalimide derivatives, well-known intermediates in synthetic, pharmaceutical, and materials chemistry. Although phthalimide is traditionally employed as a protecting group for amines via the Gabriel synthesis, isoindolinone offers a valuable alternative. Through a modified Gabriel-like approach, isoindolinones can serve as more …

Insights Into The Radiation Chemistry Of Flash Radiation Therapy, Alan E. Lopez Hernandez

Dissertations and Theses (Open Access)

Purpose: FLASH radiation therapy (FLASH-RT) is an emerging modality that delivers radiation at ultra-high dose rates (UHDR) and has shown consistent normal tissue sparing while preserving tumor control compared to conventional RT—a phenomenon termed the FLASH effect. Despite promising results, the mechanisms behind the FLASH effect remain unclear. Many hypotheses point to radiolytic interactions, but experimental validation is limited. This work aims to develop a robust experimental platform to evaluate the relationship between radiolytic species production and physical beam parameters relevant to FLASH-RT, alongside dosimetry tools for reliable UHDR beam characterization.

Methods: A beam collector (BC) Faraday cup detector was …

Mechanistic And Evolutionary Insights Into A Group Of Nicotine And Hydroxynicotine Degrading Flavoenzymes, Zhiyao Zhang

Dissertations

Flavoprotein amine oxidases (FAOs) are key enzymes in various kinds of metabolic pathways, mediating redox reactions via flavin cofactors. While most FAOs function as oxidases that readily reduce oxygen to hydrogen peroxide, a few outliers of the FAO family act as dehydrogenases that suppress the reaction with oxygen. The molecular basis for this divergence in function remains poorly understood.

The work presented in this study investigates the fundamental mechanisms of how flavincontaining enzymes activate or suppress their reaction with different electron acceptors to achieve high turnover rates. The overall body of work is divided into three different sections that (1) …

Drug Delivery, Disulfide Crosslinked Hydrogel Coating For Polydimethylsiloxane (Pdms) Implant Materials, Paul A. Contos, Paul Anthony Contos

Master's Theses

Though polydimethylsiloxane (PDMS) is often used in medical devices due to its desirable mechanical properties and biocompatibility, its surface is often prone to bacterial adhesion. This is especially a problem for catheters, where bacteria can adhere and form biofilms that can in turn result in Urinary Tract Infections (UTI). In order to deter the presence of UTI causing bacteria on PDMS catheters, methods were developed to formulate a disulfide crosslinked hydrogel coating and create a methodology to allow adhesion to a PDMS substrate. The hydrogel coating discussed in this paper will be synthesized by chemically crosslinking stimuli-responsive vesicles, that carry …

Melts To Solutions: Structure, Dynamics, And Response Of Polyelectrolytes, Shalika Meedin

All Dissertations

The current research elucidates the changes in the structure and motion of polyelectrolytes as they are perturbed by solvents and shear flows. Polyelectrolytes are macromolecules whose backbone consists of long, predominantly hydrocarbon chains, substituted by ionizable groups, which tend to dissociate into ions in polar solvents. Their properties result from a delicate balance of elastic energy that arises from the polymeric backbone and electrostatic forces, which stem from the ionizable groups. Though polyelectrolytes have an immense potential to propel numerous technologies, from clean energy to drug delivery systems, understanding the delicate balance between the properties of the polymer backbone and …

Enhancing Gaas Solar Cell Efficiency Through Nanostructured Features: A Comprehensive Review Of Recent Advances, Challenges And Future Outlook, Mohammad Nur-E-Alam, Boon Kar Yap, Tiong Sieh Kiong, Mohammad Khairul Basher, Tarek Abedin, Mohammad Aminul Islam, Mohd Adib Ibrahim, Mayeen Uddin Khandaker, Narottam Das

Research outputs 2022 to 2026

This article aims to provide a synopsis of recent advances in the use of nanostructured features to augment the conversion efficiency of gallium arsenide (GaAs) solar cells. GaAs are a very well-known and highly advantageous material for solar cells because they possess an extraordinary bandgap (i.e., approximately 1.4 eV), wide spectral absorption coefficient, and favorable carrier mobility. Numerous studies have explored the use of nanostructures, such as antireflection (AR) nanofilms/nanocoatings, nanoparticles (NPs), and nanogratings (NG), to improve the conversion efficiency of GaAs-based solar cells. These structures are generally designed to enhance light transmission capacity and absorption while reducing light reflection …

Crystal Structures Of Escherichia Coli Glucokinase And Insights Into Phosphate Binding, Joseph Andrews, Joshua Sakon, Chenguang Fan

Chemistry & Biochemistry Faculty Publications and Presentations

Here, we report the crystal structure of Escherichia coli glucokinase (GLK), which has phosphate bound in the cleft between the alpha and beta domains adjacent to the active site. A ternary complex consisting of GLK, glucose and phosphate is also reported in this work. Diffraction data were collected at 2.63 angstrom resolution for the phospate-bound form (R-work/R-free = 0.191/0.230) and at 2.54 angstrom resolution for the ternary complex (R-work/R-free = 0.202/0.258), both at 297 K. A B-factor analysis of the phosphate-bound GLK structure revealed consistently lower values for phosphate-interacting basic residues in the alpha 4, alpha 5 and alpha 9 …

Direct Photopatterning Of Quantum Dots Via Thiol-Yne Click Chemistry, Nicholas Langer, Ofer Kedem

Chemistry Faculty Research and Publications

Functional nanomaterials are revolutionizing electronic devices such as displays and photovoltaics, yet existing semiconductor manufacturing methods struggle to adapt to the unique properties of nanoparticles. In particular, quantum dots (QDs) display density-dependent properties such as tunable energy transfer, yet current preferred methods of producing QD patterns lack control over the density of QDs deposited in specific locations on a surface. Here, we present a photochemical method to generate QD patterns directly from solution onto a functionalized surface, which enables density control. The overall dose of light used in the pattern (visible or UV) determines the surface density of deposited QDs …

Advanced Analytical Biosensing For Cancer Detection And Neural Diagnostics Using Tapered Optical Fiber (Tof), Protonic, And High Throughput Microplate –Based Technologie, Bayan Hassan Alharbi

Chemistry & Biochemistry Theses & Dissertations

This dissertation investigates the development and application of advanced biosensing technologies to enhance early disease detection, neurological diagnostics, and bioactive compound evaluation. The research spans four key areas. First, it introduces tapered optical fiber (TOF)-based plasmonic biosensors for the non-invasive detection of prostate cancer, demonstrating high sensitivity and specificity compared to conventional diagnostic methods.

Second, it explores the use of fluorescent biosensors to test the Transmembrane Electrostatically Localized Proton (TELP) theory, shedding light on the role of localized protons in neuronal signaling and energy transfer. Third, the work presents a high-throughput, microplate-based biosensing platform for analyzing mitochondrial function under nanosecond …

Computational Investigation Of Energetic Materials: Influence Of Electronic And Steric Properties On Sensitivity And Decomposition Mechanisms, Elizabeth Ruth Zengel

Chemistry & Biochemistry Theses & Dissertations

Developing novel high energy density materials (HEDMs) requires knowledge of the causes and mechanisms of detonation. These chemical events are almost instantaneous and involve the release of a large amount of energy, which limits the experimental studies that can be performed on them. Computational methods including density functional theory (DFT) and molecular dynamics (MD) simulations have been used to investigate trigger bonds, those which break to initiate detonation. These bonds are commonly found within explosophores, substituents that increase the explosive potential of a molecule.

The Wiberg bond index (WBI) is an estimation of orbital overlap and bond strength between two …

Highly Contaminated Sediments From The Gowanus Canal (New York) Superfund Site: An Environmental Forensic Approach, Michael A. Kruge, Kevin K. Olsen, Eric A Stern, Maria Mastalerz, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The 2.5 km long Gowanus Canal (Brooklyn, NY, USA) is a severely contaminated urban waterway dating from the mid-19th century, listed as a US Environmental Protection Agency (USEPA) Superfund site since 2010. Applying an environmental forensics approach to the extensive USEPA data set, we detect systematic variations in parent PAH ring number distributions in the canal sediments, as well as an extraordinary enrichment in organic carbon. We subjected a supplemental sample set to a more detailed analysis by quantitative pyrolysis-GC-MS, Rock-Eval pyrolysis, and organic petrology. With these sensitive methods, we can confirm the alkyl-PAH fingerprint of coal tar (a legacy …

Green Innovation: Optimizing The Potential Of Plastic Waste As An Alternative To Fossil Fuels, Hani Alfiyani, Evi Gusmayanti, Nelly Wahyuni

Journal of Environmental Science and Sustainable Development

Plastic bag waste has the potential to be converted into alternative fuel oil through the pyrolysis method. This study applies the principle of thermal pyrolysis, conducted without oxygen, at the Edelweis Integrated Waste Management Site. The purpose is to analyze the characteristics of fuel oil derived from plastic bag waste based on parameters such as density, viscosity, calorific value, and acid number, as well as to estimate the potential fuel oil yield from plastic bag waste in Pontianak City. The results show that the density, viscosity, and calorific value of the produced fuel oil meet or closely approach standard requirements. …

Non-Spectator Behavior Of A Neutral Phosphine Ligand Driven By A Redox-Active Boron Cluster, Jared R. Riffle, Cash L. Jowers, Sarah Luna, Mark D. Smith, Dmitry V. Peryshkov

Faculty Publications

A new concept of ligand ambiphilicity that relies on the redox behavior of the indirectly coordinated boron cluster scaffold instead of the direct involvement of a single center in a ligand is introduced. A copper(I) complex of a carboranyl-based triphosphine, [t^BuP-closo-{C₂B₁₀}-^PhP-closo-{C₂B₁₀}-t^BuP]CuPF₆, in acetonitrile solution coordinates an exogenous X− anion (X− = Cl− or N3−) at the phosphorus center of the ligand and not at the cationic metal site to form [t^BuP(X)-nido-{C₂B …

Computational And In Vitro Investigation Of P. Crocatum Bioactive Compounds As Pancreatic Lipase Inhibitors, Gusnia Meilin Gholam, Dimas Andrianto, Dewi Anggraini Septaningsih, Mega Safithri

Karbala International Journal of Modern Science

Obesity, a prevalent metabolic disorder characterized by excessive fat accumulation, can severely affect overall health if left untreated. This study investigated the potential of a 70% ethanol extract from Piper crocatum (red betel) leaves as an in vitro inhibitor of pancreatic lipase (PL), supported by computational analyses to identify alternative compounds to orlistat. The phytochemical profile was characterized using LC-MS/MS, revealing alkaloids and terpenoids with contents of 1.1 ± 0.01 mg CE/g and 3.14 ± 0.3 mg UAE/g, respectively. The extract exhibited 49 ± 9.1% inhibition of PL activity. Molecular docking identified three promising compounds: calanolide A (10.43 kcal/mol), myricanone …

A Mutational Analysis Of Thatisin: How Single Point Mutations Impact The Biosynthetic Process Of A Group 16 Graspetide, John F. Boynton Jr

Chemistry and Chemical Biology ETDs

Abstract:

Graspetides are a family of Ribosomally synthesized and Post-translationally modified Peptide (RiPP) natural products named for their ATP Grasp Macrocyclases. We identified several Graspetide Biosynthetic Gene Clusters containing common double glycine cleavage motifs and attempted characterization of the mature Graspetides. One of the resulting peptides, Thatisin, has a topology with two interlocking macrolactones installed by a single ATP Grasp Ligase named ThtC. Here we use single and double point mutations to observe the impact or variation on the installation of these macrocycles. Alanine scan mutagenesis is used to assess leader peptide residues in the precursor peptide ThtA to determine …

A Systematic Approach To The Characterization Of Liquid-Vapor Coexistence In Platinum, Meghan K. Lentz

Physics & Astronomy ETDs

Platinum is a material standard used in high pressure and shock compression experiments at Sandia National Laboratories. During experiments, materials are subjected to a very large range of thermodynamic conditions, during which materials regularly enter the liquid-vapor coexistence region. Despite its status as a standard, the region around the liquid-vapor critical point is poorly understood for platinum, with reported critical temperatures spanning approximately 7000 K. In this dissertation we conduct density functional theory based molecular dynamics (DFTMD) simulations for platinum for a range of temperatures and densities near liquid-vapor coexistence. The phase diagram for platinum is refined near the critical …

Numerical Simulation Of The Pitting Corrosion Behavior Of Stainless Steel Bellows Influenced By Varying Liquid Film Thicknesses, Lu-Jun Ren, Guo-Min Li, Zhen-Xiao Zhu, Hai-Yan Xiong, Bing Li

Journal of Electrochemistry

To advance the understanding of the corrosion behavior of stainless steel bellows in marine atmospheric environments and enhance the precision of service life predictions, this study employs finite element simulations to investigate the pitting corrosion rates and pit morphologies of bellows peaks and troughs under varying electrolyte film thicknesses. The model incorporates localized electrochemical reactions, oxygen concentration, and homogeneous solution reactions. For improved computational accuracy, the fitted polarization curve data were directly applied as nonlinear boundary conditions on the electrode surface via interpolation functions. Simulation results reveal that the peak regions exhibit faster corrosion rates than the trough regions. With …