Chemistry Commons^™

Electrochemical Characterization Of Surface-Immobilized Metal Nanostructures: Stability, Atomic Level Doping, Catalysis, And Sensing Applications., Badri Prasad Mainali

Electronic Theses and Dissertations

This dissertation has two main themes. The first theme involves voltammetric analysis of the stability of Au nanoparticles (NPs) under electrochemical and thermal treatment as a function of size, ligand stabilizer, and atomic composition. The second theme involves the use of Au NPs, electrophoretic deposition (EPD), and anodic stripping voltammetry (ASV) for electrochemical detection of analytes. The electrochemical size stability of 4.1, 15.1, and 50.3 nm average diameter Au NPs upon treatment with multiple electrochemical oxidation-reduction cycling in acidic electrolyte is monitored by observing changes in the peak oxidation potential (E_p) in ASV and the electrochemically measured surface …

Micelles And Lipid Nanoparticles: Catalysis And Biomedical Application., Faisal Ibrahim

Electronic Theses and Dissertations

RNA-based therapeutics is a rapidly expanding field due to its enormous potential for treatment of diseases through knockdown of genes or expression of therapeutic proteins. However, due to the overall negative-charge of an RNA molecule, RNA-based therapeutics must rely on delivery systems to overcome the various biological barriers for ultimate release of an RNA payload into the cytosol. Over the past three decades, the development of lipid-based RNA delivery systems, especially lipid nanoparticles (LNPs), have been comprehensively studied due to their unique properties. LNPs represent the most widely used delivery systems for RNA-based therapeutics, as evidenced by the clinical approvals …

Computational And Experimental Studies Of Functionalized Phenolic Tertiary Phosphine Oxides As Organocatalysts For The Redox-Neutral Mitsunobu Reaction, Sadie Brown

Electronic Theses and Dissertations

The purpose of this thesis was the identification of a more efficient catalyst analog that could perform the redox-neutral Mitsunobu reaction, which was achieved via two synthetic pathways: elimination-addition and addition-rearrangement. Furthermore, a computational investigation was conducted on the conflicting interpretations of the catalytic cycle. Our research group replicated Houk et al. work, as well as expanded the computations to examine the influence different functional groups had on the ground state and transition state structures. Important ground state and transition state structures were determined, which provided a more energetically favorable pathway of the catalytic cycle. Experimental work demonstrated that both …

Quantification Of Persistent Organic Pollutants In Various Matrices Using Stir Bar Sorptive Extraction And Isotope Dilution Mass Spectrometry, Weier Hao

Electronic Theses and Dissertations

A method was developed to quantify persistent organic pollutants (POPs) in a wide range of matrices including wastewater, dietary supplements, and human whole blood using stir-bar sorptive extraction, GC-MS/MS, and isotope dilution mass spectrometry (IDMS). The method enabled accurate, precise, sensitive, and efficient quantification of POPs in these matrices. Compared with calibration curves, IDMS provided measurements with a higher level of accuracy and precision, especially at lower measured concentrations. The use of GC-MS/MS enabled a lower limit of quantification compared with GC-MS. A reverse-IDMS method was performed to further eliminate biases from the labelled concentrations of the commercially available standards. …

Electrodeposition Of Hydrogen Molybdenum Tungsten Bronze Films And Electrochemical Reduction Of Carbon Dioxide., Mohammad Bajunaid

Electronic Theses and Dissertations

The foremost aim for performing this study was to focus on the electrodeposition of mixed hydrogen molybdenum tungsten bronze films, which have the potential for e^– transfer interactions carrying out the reduction of carbon dioxide. A yellow peroxymolybdic tungstate solution was prepared and used for the electrodeposition of hydrogen molybdenum tungsten bronze films on conductive carbon paper. Electrodeposition was carried out at -2.0 V from 20 - 120 minutes to determine the effect of deposition time on film thickness and CO₂ reduction. These films were characterized by X-ray photoelectron spectroscopy. The deposited films served as a working electrode …

Theranostic Nanoparticles Folic Acid-Carbon Dots-Drug(S) For Cancer, Godwin Kweku Babanyinah

Electronic Theses and Dissertations

This study aims to prepare theranostic nanoparticles (NPs) that are expected to increase cancer diagnostics and therapeutic efficacy. We prepared the NPs constituting carbon dots (CDs) as an imaging agent, folic acid as a targeting agent, doxorubicin (DOX), or gemcitabine (GEM) as chemotherapy agents. The NPs include noncovalent FA-CDs-DOX, covalent CDs-FA-DOX, and covalent FA-CDs-GEM. Through ultraviolet-visible spectroscopy, fluorescence spectroscopy, and Fourier transform-infrared spectroscopy, the fabrication of these NPs was confirmed. It was discovered that the high drug loading efficiency is the noncovalent series while the high drug loading capacity is the covalent series The in-vitro pH-dependent drug release data indicate …

Simulation Of The Interaction Between Striated Muscle Unc-45 And Transcription Factor Gata-4, Drake Alexander Duncan

Electronic Theses and Dissertations

Striated Muscle UNC-45, also known as UNC-45b, is an important protein that acts as a chaperone for myosin in cardiac and skeletal muscles, binding to myosin at its C-terminal UCS domain and regulating its assembly into thick filaments and sarcomeric structures. The UCS domain contains a large loop that is believed to be the first point of interaction between myosin and UNC-45b. GATA-4 is an essential transcription factor that facilitates transcription of several genes in cardiac development, particularly alpha-heavy chain myosin in heart tissue. Recently, studies have shown that there is interaction of GATA-4 with UNC-45b and that GATA-4 binds …

A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali

Electronic Theses and Dissertations

Photodynamic therapy (PDT) has become a widely popular therapeutic approach for treating various types of cancer over the past several decades. PDT utilizes a photosensitizer, visible light, and oxygen, to produce reactive oxygen species (ROS) which can be used to treat cancer and inhibit growth of bacteria. In this study, a multifunctional solution that is comprised of Fe(III) ions, cationic meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (TMPyP), and 1,5-dihydroxynapthalene (1,5-DHN), was shown to produce reactive oxygen species (ROS) such as singlet oxygen (¹O₂) or hydroxyl radicals (ȮH) in aerobic or anaerobic environments, respectively, and in both environments, 1,5-DHN was oxidized …

Investigating The Role Of Charge Separation In Triplet State Formation In Zinc Dipyrrin Photosensitizers, Irene Y. Dzaye

Electronic Theses and Dissertations

About 85% of the world’s energy is derived from non-renewable sources—coal, petroleum, and natural gas. Solar photocatalysis is one way to potentially generate cheap renewable fuels by harnessing energy from the sun using a photosensitizer and converting it into chemical energy. The efficiency of a photosensitizer depends on its capacity to form a prolonged triplet excited state. Zinc dipyrrin complexes have the potential to be efficient sensitizers for reductive photochemistry, but their ability to form long-lived triplet excited states still needs extensive research. The overall aim of this research is to probe the role charge separation plays in the formation …

Photoassisted Synthesis Of Complex Polyheterocycles Via Rational Design Of Tailored Photoprecursors, Tina Alanna Holt

Electronic Theses and Dissertations

Natural products remain the most common source for drug leads, although diversity-oriented synthesis of unnatural complex molecules is gaining momentum. Our lab has been developing experimentally simple and straightforward approaches to complex molecular architectures via photochemical reactions involving a minimal number of experimental steps. In order to achieve this, photoprecursors were assembled via high yielding reactions. Next, we deployed photoinduced cycloadditions to create complex 3-dimentional structures. Lastly, with this obtained primary photoproduct, post-photochemical transformations were used to further grow its scaffold complexity.

One method to increase scaffold complexity is the [4+2] intramolecular cycloadditions of azaxylylenes, which are developed through standard …

Epr Relaxation Of Modified Triphenylmethyl And Nitroxide Radicals, Whylder Moore

Electronic Theses and Dissertations

Trityl and nitroxide radicals are widely used as probes in chemical and biochemical systems. Understanding of factors that impact the electron spin relaxation for these radicals is important for selection of probes and experimental operating conditions. It has been previously reported that ¹³C isotope enrichment of the central carbon of the trityl yields a highly sensitive micro viscosity probe. It was important to characterize the impact of this substitution on the relaxation processes in fluid solution and immobilized samples.

Electron spin relaxation times for perdeuterated Finland trityl 99% enriched in ¹³C at the central carbon (¹³C …

Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown

Electronic Theses and Dissertations

Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …

Elucidating The Interfacial Interactions Between Biomacromolecules And Functionalized Pamam-Based Materials For Biomedical Applications, Briana L. Simms

Electronic Theses and Dissertations

Polyamidoamine (PAMAM) is a dendrimer structure with a polypeptide backbone architecture. It has been utilized in a wide variety of applications but has found significant utility in biomedical applications. PAMAM has been studied extensively due to its globular structure that is similar to proteins found in the body. The branched architecture and overall size provide a favorable environment for host-guest interactions and allows for the loading of small molecules for therapeutic delivery. Although PAMAM has many benefits for use in the area of therapeutic delivery, a primary area of concern for this molecular architecture is the terminal amines that serve …

A Spectroscopic And Quantum Chemical Investigation Into The Noncovalent Interactions And Charge Accommodation Of Biomolecules And Their Building Blocks In Various Environments, Ashley Elizabeth Williams

Electronic Theses and Dissertations

As optical measurements have grown increasingly more precise with the rage of the technological revolution, the computer’s ability has matched in computing speed to produce accurate quantum chemical predictions of systems ranging from the atomic to multi-molecular levels. Application of spectroscopy in the investigation of the structure and function of biomolecules and their building blocks has a rich literature background, with applications among cancer research, charge transfer and energy storage, and drug design and delivery. The focus of this dissertation is thus a quantum chemical and/or spectroscopic investigation of a series of biomolecules which include the vibrational band positions of …

Therapeutic Immunoglobulin G Surface Mobility Promotes Antibody-Dependent Cellular Phagocytosis By Arp2/3 And Syk Mediated Rearrangement Of Fcγ Receptors, Seongwan Jo

Electronic Theses and Dissertations

Therapeutic antibodies are rapidly growing class of drugs for treating cancers and immunological disorders by targeting specific antigens or blocking certain pathway to inhibit the tumor growth. In cancer immunotherapy, it was found that Fcγ receptor (FcγR) in immune cells play an important role in antibody dependent cell toxicity against tumor cells. Therefore, understanding FcγR activation mechanism, which requires ligation with immunoglobulin (IgG), is crucial to enhance potency of therapeutic antibodies. One crucial immune responses triggered upon FcγR ligation with IgG is phagocytosis which indicates clearing targets by engulfment. It is known that FcγRs form microclusters which gets rearranged during …

Analysis Of Volatile Organic Compounds: Petroleum Emissions And Microbial Degradation, A K M Ahsan Ahmed

Electronic Theses and Dissertations

Volatile organic compounds (VOCs) are abundant in nature and can occur in various forms in a wide variety of sources. Petroleum is one of the major sources of VOCs. Petroleum being the most widely used energy resources of the world, often released to the environment due to emission and leakage or accidental spillage during exploration, transportation and manufacturing. Once released to the environment, petroleum poses a serious threat to the environment due to some of its toxic organic components. Therefore, the analysis of petroleum is critical to understand its effect on the environment and remediation. This dissertation is focused on …

College Students Conceptions Of Particulate Nature Of Matter And The Impact On Research Instrumentation, Bridget Klutse

Electronic Theses and Dissertations

The main objective of this research was to explore the understanding and conceptions of Particulate Nature of Matter (PNM) with Chem 115 L students as the participants. Conceptions were defined specifically as beliefs and alternative beliefs about topics. The research also assessed the impact of analytical instrumentation in the chemistry laboratory on learning chemistry concepts. Eight questions (8) with multiple choice answers were administered to 10 students at the beginning and after the Fall 2018 semester via selective/purposeful sampling. Data were collected using surveys (pre- and post-surveys) and interviews (pre- and postinterviews), then analyzed quantitatively and qualitatively. The eight questions …

Novel Acetylcholine Chloride Based Water Immiscible Deep Eutectic Solvent: Formulation, Characterization And Application In Drug Solubilization, Shiksha Subedi

Electronic Theses and Dissertations

Deep eutectic solvents (DESs) are the emerging class of new and inexpensive solvents composed of two or three safe components capable of self-association through hydrogen bond interaction. The depression in the melting point characterizes DESs compared to those of the individual components. These solvents have properties like the traditionally used ionic liquids (ILs), but they can offset the significant drawbacks of ILs, such as biodegradability, toxicity, and complex synthesis. Due to these remarkable advantages, the research in DESs is increasing exponentially. However, current deep eutectic solvents still have limitations to apply to the real chemical industries due to hydrophilicity and …

Analysis Of Metabolites And Therapeutics For Toxic Inhaled Agent Exposure, Abigail Bemah Donkor

Electronic Theses and Dissertations

The inhalation of toxic inhaled agents (TIAs) such as methyl isocyanate and cyanide can compromise an individual’s general health due to their extremely toxic nature. Nonetheless, these gases are used extensively in the electronics, chemical, welding, electroplating industries, etc., increasing the risk of exposure to both civilians and industrial workers. It is therefore very crucial to develop analytical methods for TIA metabolites and therapeutic agents. Methyl isocyanate (MIC), an intermediate in the synthesis of carbamate pesticides is a toxic industrial chemical that causes irritation and damage to the eyes, respiratory tracts, and skin. Due to its reactivity with proteins, protein …

Assaying Bacillus Amyloliquefaciens Isolates 1ba And 1d3 For Biosurfactant Production And Utilization Of Petroleum Hydrocarbons And Phenolic Acids, Pavan Kulkarni

Electronic Theses and Dissertations

Several Bacillus amyloliquefaciens isolates obtained from wheat residue have been studied as biological agents to control wheat diseases. Notable traits of isolates 1BA and 1D3 include growth with high salt (10% NaCl), at temperatures up to 50°C and over a wide pH range. BIOLOG Gen III plates were used to study and further characterize Bacillus amyloliquefaciens 1BA and 1D3. Both isolates showed tolerance to high salt concentration supporting previous studies. They also grew in the presence of lithium chloride, potassium tellurite, and sodium bromate. Both isolates grew at pH 5, with almost identical carbon source utilization fingerprints. However, D-serine, quinic …

Enhanced Electrochemical And Light-Driven Co2 Reduction By Incoporating Pendant Functionality In The Second-Coordination Sphere Of Molecular Catalysts, Sayontani Sinha Roy

Electronic Theses and Dissertations

With the increase in global population and rapid industrialization, a gigantic amount of greenhouse gases is being released into the atmosphere each year. The catastrophic effect of these accumulated greenhouse gases is driving global climate change and adversely impacting our ecosystem. Popularizing the traditional renewable energy sources (such as solar and wind energy) can mitigate the problem by cutting down anthropogenic CO2 emissions, which is the major contributor to this global problem. However, the intermittent nature of these energy sources is problematic to reliably power society throughout the year. Therefore, converting CO2 to various value-added chemicals with the aid of …

An Integrative Analysis On The Role Of Notch1 And Notch3 In Musculoskeletal Disease, Haydee Magdalena Torres

Electronic Theses and Dissertations

Notch signaling is an evolutionarily conserved signaling pathway involved in cell fate decisions and cell renewal of multiple systems, including skeletal and muscle homeostasis. As the multifunctional nuclear complex of Notch1 is essential for its pathological function, identifying these interacting partners represents a potentially broad range of druggable vulnerabilities. We have completed a BioID proteomics study and found a large set of nuclear proteins associated with NOTCH1, including transcriptional regulators and epigenetic modulators, of which Histone Deacetylase 1 (HDAC1) is a promising interacting partner of Notch1. Our Cytoscape analysis predicted HDAC1 to be a top critical node in an activated …

Polyester-Pamam “Janus-Type” Linear-Dendritic Blockopolymers (Ldbcs) As Next Generation Biomaterials, Indika Chandrasiri

Electronic Theses and Dissertations

Nanomedicine is defined as the application of knowledge and tools of nanotechnology for disease treatment, diagnosis, monitoring, delivery, and sensing. Rapid advances in polymer chemistry and nanotechnology have led to an extensive development of polymeric-based therapeutic systems for nanomedical applications. Compared to traditional molecular-based therapies, polymers facilitate a higher level of versatility and functionality, such as simultaneous imaging and delivery. In particular, amphiphilic diblock copolymers and their self-assemblies have shown apparent success in nanomedicine owing to their ability to provide narrow molar mass distributions and highly ordered nanoscale multimolecular aggregates, including micelles and vesicles. However, engineering these polymeric materials to …

Advancements Toward Sustainable Solar Fuel Production Utilizing Reductive Homogeneous Electro- And Photocatalysis, Hunter Pratt Shirley

Electronic Theses and Dissertations

Molecular CO2 and H+ reductive catalysts, whether they be electro- or photocatalytic, have been shown to be possible routes of harnessing solar energy in a clean, renewable manner. There are few electrocatalysts operating at reasonable overpotentials to prove useful in artificial photosynthetic systems, and there are a number of environmental factors within these systems that have yet to be evaluated. Photo-driven catalysis is rare, difficult to control, and rarely provides high-value CO2 reduction products. I report herein an exceptionally low overpotential H+ reduction catalyst, a method of modulating electrocatalysts in-situ to improve performance, a first-of-its-kind mononuclear proton reduction photocatalyst, a …

Application Of Passive Air Samplers For Atmospheric Research, And Determination Of Metals In Tree Rings And Marine Sapropel By Icp-Ms, Byunggwon Jeon

Electronic Theses and Dissertations

This research focuses on studies of atmospheric mercury (Hg) using passive air samplers (PAS) and studies of trace elements in tree cores and sediment using inductively coupled plasma mass spectrometry (ICP-MS). Mercury is a toxic element that is dispersed globally through the atmosphere. Accurately measuring airborne Hg concentrations aids understanding of the pollutant’s sources, distribution, cycling, and trends. Mercury PAS are designed to capture gaseous elemental mercury (GEM) at a known rate. Compared to active air sampling the low-cost of PAS allows for greater spatial coverage. We used a commercially available Hg PAS (MerPAS®) and observed differences in GEM between …

Advanced Analytical Techniques For The Analysis Of Therapeutics Of Toxic Inhalation Agents And Pharmacokinetic Investigation, Subrata Bhadra

Electronic Theses and Dissertations

Toxic inhalation agents (TIAs), (i.e., cyanide (CN) and reduced sulfur compounds (RSCs)), including hydrogen sulfide (H2S) and methanethiol (MT)) are extremely poisonous upon exposure. Many TIAs act by inhibiting mitochondrial cytochrome c oxidase, resulting in cellular hypoxia, cytotoxic anoxia, apnea, respiratory failure, cardiovascular collapse, seizure and potentially death. CN is generated in structural fires and cigarette smoke as well as in mining, electroplating and polymer processing, whereas H2S and MT are found in petroleum, oil and natural gas, waste treatment facilities and decaying organic matter. All are common occupational gas exposure hazards in chemical industries and for first responders, including …

Accurate Quantitation Of Hexavalent Chromium For Reference Standard Certification And Quality Control Testing Using Speciated Isotope Dilution Mass Spectrometry, James E. Henderson

Electronic Theses and Dissertations

The ability to perform accurate, repeatable, and defensible elemental and molecular speciated analysis is immensely significant for measurements that support human health, environmental science, and industry. This is especially true since trivalent chromium [Cr(III)] is necessary for proper nutrition, while hexavalent chromium [Cr(VI)] is extremely toxic, genotoxic, and carcinogenic. The main challenges associated with speciated analysis are related to reactive species that are continuously transformed or converted to other species during sample processing. Accurate determination of Cr(III) and Cr(VI) species require a method that is capable of monitoring and correcting for interconversion, bias, and instrumental error. Traditional quantitative methods, such …

Functionalized Materials From Atom Transfer Radical Processes, Sean Fischer

Electronic Theses and Dissertations

This work is focused on the synthesis, characterization, and application of functionalized materials prepared from atom transfer radical processes. Atom transfer radical processes encompass both atom transfer radical addition (ATRA) and polymerization (ATRP) reactions, both of which are catalyzed by ppm amounts of copper complexes. The synthetic efforts of ATRA include increasing adduct selectivity through optimization of reaction conditions to generate small molecules in high to moderate yields. ATRA provides retention of the halogen moiety, which is an attractive functional group that can be further modified with other transformations. Specifically, the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) allows for the realization …

Atom Transfer Radical Processes: From Catalyst Design To Polymer Synthesis, Characterization, And Application, Michael Novak

Electronic Theses and Dissertations

Due to the toxicity of heavy metals and their prevalence in the environment there exists a need to develop highly active transition metal catalysts ultimately reducing the amount needed for chemical transformations. Additionally, there is interest in the scientific community for creating new materials that can remove these pollutants from industrial wastewater prior to its release into the environment. The work presented here focuses on the reduction and removal of heavy metals from industrial hazardous waste by designing novel highly active catalysts and developing polymeric adsorbents.

Highly active catalyst complexes consisting of novel hybrid ligands, 2-(dimethylamino)ethyl-bis-[2-(pyridylmethyl)amine] (M1-T2), and bis[2-(dimethylamino)ethyl]-2-(pyridylmethyl)amine (M2-T1), …

Control Of Corrosion On Ss316l Using Surface Initiated Polymers, Alexander Rupprecht

Electronic Theses and Dissertations

Pitting corrosion is arguably one of the most destructive and dangerous forms of corrosion, resulting in damage to structures, the environment, and public health. In addition, damage caused to structures such as bridges, pipelines, and boats, corrosion also has a profound effect on the biomedical community. Implanted metallic devices (i.e., vascular stents and artificial joints) are prone to pitting corrosion caused by aggressive ions present in extracellular fluid. To provide a corrosion-resistant surface on SS316L, films of poly(styrene), poly(methyl acrylate), and poly(methyl methacrylate) were formed using surface-initiated atom transfer radical polymerization (SI-ATRP). The resulting hydrophobic polymer films had a fractional …