Physical Sciences and Mathematics Commons^™

High Resolution Mass Spectrometry As A Platform For The Analysis Of Polyoxometalates, Their Solution Phase Dynamics, And Their Biological Interactions., Daniel T. Favre

Doctoral Dissertations

Polyoxometalates (POMs) are a class of inorganic molecule of increasing interest to the inorganic, bioinorganic and catalytic communities among many others. While their prevalence in research has increased, tools and methodologies for the analysis of their fundamental characteristics still need further development. Decavanadate (V10) specifically has been postulated to have several unique properties that have not been confirmed independently. Mass spectrometry (MS) and its ability to determine the composition of solution phase species by both mass and charge is uniquely well suited to the analysis of POMs. In this work we utilized high-resolution mass spectrometry to characterize V10 in aqueous …

Role Of Relative Humidity In New Particle Formation From Ozonlysis Of Atmospheric Volatile Organic Compounds, Christopher Snyder

Graduate College Dissertations and Theses

The impact of relative humidity (RH) on organic new particle formation (NPF) from ozonolysis of biogenic volatile organic compounds (BVOCs) remains an area of active debate. Previous reports provide contradictory results indicating both depression and enhancement of NPF under conditions of moderate RH, while others ignore the potential impact. Only several reports have suggested that the effect may depend on absolute mixing ratio of the precursor volatile organic compound (VOC, ppbv). However, before any experiments could be completed, development of new methods was necessary to overcome the limitation of sampling ultrafine nanoparticles (<50 nm aerodynamic diameter) with aerosol mass spectrometry. This dissertation includes a report on a new Particle Growth Apparatus (PaGA) that artificially grows particles from as small as 17 nm to over 110nm. Considerable effort was made to identify the most suitable growth matrix (squalane) and optimize particle growth for reproducibility and sensitivity.

The PaGA was then utilized in the …

Investigating The Effect Of Relative Humidity On Organic New Particle Formation From The Dark Ozonolysis Of Biogenic Volatile Organic Compounds, Austin Callum Flueckiger

Graduate College Dissertations and Theses

Solid or liquid particulate matter suspended in the air, also known as atmospheric aerosols, are a ubiquitous component of Earth’s atmosphere. It is important to understand the chemical and physical processes that lead to the formation of these aerosols as they have an impact on climate health and human health. An important subset of atmospheric aerosols are secondary organic aerosols (SOA) that form from the gas-phase oxidation of volatile organic compounds (VOCs). VOCs can be emitted via biogenic and anthropogenic pathways, however, global estimates place biogenic sources as the major contributor. Although widely studied, some of the fundamental mechanisms that …

Development Of Novel Protein Digestion And Quantitation Methods For Mass Spectrometic Analysis, Yongling Ai

Dissertations

Proteins are the workhorses of biology, playing multifaceted roles in maintaining cellular function, signaling, and response to environmental cues. Understanding their abundance and dynamics is pivotal for unraveling the complexities of biological processes, which underpins the foundations of molecular and cellular biology. Accurate measurement of protein quantities provides insights into cellular homeostasis, facilitates the discovery of biomarkers, and sheds light on the molecular mechanisms of diseases, bridging the gap between the molecular intricacies of proteins and their functional consequences in health and disease. The evolution of protein quantitation methodologies, from classical colorimetric assays to sophisticated mass spectrometry-based approaches, has expanded …

Investigation Of Zinc And Iron In Wildflower Honey, Savannah Simpson

Honors Theses

Honey acts as a valuable food source for both animals and humans. When found in contaminated environments, there is an increased likelihood that honey samples will have high metal concentrations. It has been discovered that honey concentrations in metals can be different based on location. This experiment aims to determine the amount of two valuable metals, zinc, and iron, in various honey sources. These metals can be important to the human body because they help boost immunity and allow the body to carry out the functions required for survival. However, if these elements are present in copious quantities, then it …

Integration Of Raman Spectroscopy And Python-Based Data Analysis For Advancing Neurobiological Research, Natalie E. Dunn

Doctoral Dissertations

The field of Raman spectroscopy continues to expand into biological applications due to its usefulness as a non-invasive technique that can be utilized qualitatively and quantitatively. However, the inherent weakness of Raman scattering leads to the need for each collected spectra to undergo a preprocessing step to remove noise, background drift, and cosmic rays. Biological research in particular needs large datasets due to the increased variability in samples. As datasets grow, the need to perform preprocessing on each individual spectra becomes daunting. Often, these steps are done by hand with the help of specialized software programs. Preprocessing can be accelerated …

A Noninvasive Urine-Based Method For Kidney Cancer Early Detection, Kiana Holbrook

Open Access Theses & Dissertations

Based on the traditional serological uses to obtain diagnoses of cancer and biopsy techniques, common cancer detection could be not only invasive but expensive and some tests are also unreliable. Currently, urine is one of the most frequently used and collected specimens in the clinical diagnoses. While the areas of urinalysis and metabolomic profiling has received interest in the top clinical research, there are limited components to the validity, specificity, as well as sensitivity of endogenous urine substrates to detect early stages of cancers. Although there is research showcasing that urine is impacted by age, cancer type, geographical location, and …

Studies On Electrochemical Hydrogen Isotope Separation, Liyanage Mayura Sankalpa Silva

All Dissertations

Graphene-integrated Proton Exchange Membrane (PEM) electrochemical cells have emerged as a novel area of scientific investigation in the realm of hydrogen isotope separation. Chemical Vapor Deposited (CVD) graphene has been especially useful due to its large-scale production capability for scaling-up purposes. The research described in this dissertation explores the role that inadvertent introduction of cations, notably ammonium and copper, during the CVD graphene transfer onto PEM substrates, such as Nafion, might play in affecting hydrogen ion transport and isotope separation in PEM electrochemical cells. An extensive review of existing literature exposed a gap concerning unintentional cation introductions during graphene transfer, …

Electrodeposition Studies Of Gold Nanoparticles And Alginate Hydrogel Films., Harikrishnan Nambiathan Nambiar

Electronic Theses and Dissertations

This dissertation investigates the electrochemical deposition (ECD) and electrophoretic deposition (EPD) processes involving citrate (cit)-stabilized Au nanoparticles (NPs) and calcium alginate (Ca-Alg-Au NP) hydrogel films. The first part of the dissertation investigates the influence of NP size, surface area (SA) coverage, and ligand stabilizers on the electrochemical growth of Au on Au NPs, aiming to enhance our understanding of the growth process during the nucleation and growth of metal NPs. The growth kinetics depend on Au NP size (4 nm > 15 nm > 50 nm) for a constant SA coverage, as determined by the overpotentials for ECD. The growth rate increases …

The Influence Of Ion-Ion Correlations On Conductivity In Concentrated Ionic Systems, Md Dipu Ahmed

Masters Theses

This study delves into the fascinating realm of concentrated ionic systems, such as ionic liquids, superionic materials, organic ionic plastic crystals, and polyelectrolytes, which hold immense potential for energy storage applications. The focus is on understanding the intricate role of ionic correlations in shaping their ionic conductivity behavior. These correlations can either boost or impede conductivity, yet their underlying mechanisms remain elusive. Through extensive investigation of various materials, including ionic liquids with differing anionic masses, pure organic ionic plastic crystals, and doped systems, this research employs advanced techniques like dielectric spectroscopy and innovative momentum conservation models to quantify these correlations. …

Reactive Chemistries For Protein Labeling, Degradation, And Stimuli Responsive Delivery, Myrat Kurbanov

Doctoral Dissertations

Reactive chemistries for protein chemical modification play an instrumental role in chemical biology, proteomics, and therapeutics. Depending on the application, the selectivity of these modifications can range from precise modification of an amino acid sequence by genetic manipulation of protein expression machinery to a stochastic modification of lysine residues on the protein surface. Ligand-Directed (LD) chemistry is one of the few methods for targeted modification of endogenous proteins without genetic engineering. However, current LD strategies are limited by stringent amino acid selectivity. To bridge this gap, this thesis focuses on the development of highly reactive LD Triggerable Michael Acceptors (LD-TMAcs) …

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Protein Stability In Solution And In The Gas Phase., Yousef Haidar

Electronic Thesis and Dissertation Repository

Electrospray Ionization mass spectrometry (ESI-MS) is widely used for probing proteins, yet many aspects of this technique remain elusive. Using MS, ion mobility spectrometry (IMS), and circular dichroism (CD) spectroscopy, this thesis sheds light on the stability differences of proteins in the gas phase and solution. After a general introduction (Chapter 1), Chapter 2 scrutinizes some aspects of native ESI. Our data highlight the significance of cone voltage in maintaining a native-like fold and show the advantage of using NH₄Ac in protein experiments. Chapter 3 focuses on hydrogen/deuterium exchange (HDX)-MS. Several studies have reported that D₂O …

Synchrotron Study Of Phase Transition And Heterostructures In Metal Oxide Semiconductors, Bingyu Dong

Electronic Thesis and Dissertation Repository

Transition metal oxides, including titanium dioxide (TiO₂), zinc oxide (ZnO) and Tin dioxide (SnO₂) are widely recognized semiconducting photocatalysts. This project engages in a detailed examination of the phase transition of TiO₂ and the synthesis of heterostructured metal oxides using an eco-friendly method of ball-milling. A variety of spectroscopy and microscopy techniques have been used to analyze the products. Synchrotron-based techniques: X-ray Absorption near-edge spectroscopy (XANES), X-ray Emission Spectroscopy and X-ray excited optical luminescence (XEOL) can demonstrate the local structure and bonding. The finding highlights a phase transition in TiO₂ and the formation of …

The Effect Of Hydrogen Peroxide On The Corrosion Dynamics Of Carbon Steel, Kwang Soak Gabriel O'Donnell

Electronic Thesis and Dissertation Repository

The Used Fuel Container (UFC) is a key barrier in Canada’s nuclear fuel disposal plan. Understanding the radiation-induced corrosion of the carbon steel (CS) vessel is critical for predicting the long-term integrity of the UFC. Developing a mechanistic understanding of CS corrosion and the effect of solution parameters is essential.

This work investigates the effects of H₂O₂, the key radiolytic oxidant, on CS corrosion dynamics in small, stagnant solutions. Elementary processes are identified, corrosion rates are calculated, and the effects of H₂O₂ concentration are investigated. Corrosion was studied by quantifying the concentrations of …

Investigating Novel Luminescent Materials Towards Applications In Light Emitting Electrochemical Cells, Kenneth Chu

Electronic Thesis and Dissertation Repository

The search for new and better luminescent materials is becoming increasingly important, as there are significant cost-savings in using luminophores that are brighter and more efficient. Carbon quantum dots (CQDs) and other luminescent materials such as Pt-Ag nanoclusters and TADF compounds are an extremely appealing alternative to existing light-emitting materials, as they are low-cost, easy to synthesize, and non-toxic.

This thesis explores the properties and performance of different luminescent materials to be used in light-emitting electrochemical cells (LECs). In this work, we focused on LECs as their low cost and ease of fabrication aligns well with the ethos of CQDs …

Chirality, Symmetry-Breaking, And Chemical Substitution In Multiferroics, Kiman Park

Doctoral Dissertations

Multiferroic materials attract significant attention due to their potential utility in a broad range of device applications. The inclusion of heavy metal centers in these materials enhances their magnetoelectric properties, yielding fascinating physical phenomena such as the Dzyaloshinskii–Moriya interaction, nonreciprocal directional dichroism, enhancement of spin-phonon coupling, and spin-orbit-entangled ground states. This dissertation provides a comprehensive survey of magnetoelectric multiferroics containing heavy metal centers and explores spectroscopic techniques under extreme conditions. A microscopic examination of phase transitions, symmetry-breaking, and structure-property relationships enhances the fundamental understanding of coupling mechanisms.

In A2Mo3O8 (A = Fe, Zn, Ni, and Mn), we use optical spectroscopy …

Inkjet-Printed Electrochemical Sensors For Lead Detection, Annatoma Arif

Open Access Theses & Dissertations

This PhD dissertation research has developed a simple, miniaturized, sensitive, selective, reproducible, and disposable 3D (inkjet printed – additive manufacturing technology) gold (Au) plated electrochemical sensor (ECS) on shape memory polymer (SMP) for aqueous lead detection. This technology has shown promising performance in the application of electrochemical sensing (lead (II) detection) due to increased effective electrode surface area (7.25 mm^2 ± 0.15 mm^2) despite miniaturizing lateral surface area (4.19 mm^2). The design, fabrication processes, optimization including bismuth functionalization, evaluation, uncertainty analysis, and cost analysis of the novel SMP based inkjet printed Au plated sensor have been delineated in this manuscript …

Removal Of Nonylphenols From Water And Wastewater Using Alginate-Activated Carbon Beads, Angelica Araly Chacon

Open Access Theses & Dissertations

The presence of contaminants of emerging concern (CECs) have been affecting water quality in recent years. The United States Environmental Protection Agency (U.S EPA) defines CECs as toxic chemicals without regulatory status and with adversely impact on the wildlife and people. Among the CECs, nonylphenols (NPs) are frequently found in all water systems and are categorized as endocrine-disrupting compounds (EDCs) due to their ability to mimic hormones causing reproductive and developmental effects in humans and animals. The main sources of discharge and distribution of NPs into the environment are wastewater treatment plants (WWTPs) which are not designed to remove them. …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Investigating The Activity Of Alternative Warheads For Targeted Covalent Inhibition Of The Inhibitor Vertebrate Lysozyme Protein From Pseudomonas Aeruginosa, Katie Hambrick

Master of Science in Chemical Sciences Theses

Pseudomonas aeruginosa (P. aeruginosa) is a Gram-negative bacterium that causes blood and lung infections in hospital environments due to its ability to survive on improperly sterilized medical equipment. P. aeruginosa has developed several multi-drug resistance mechanisms that make it very difficult to treat with current antibiotics.¹ This presents the need for a new class of antibiotics that cannot be overcome by P. aeruginosa’s mechanisms of resistance.

The primary goal of this project was to develop a small library of inhibitors that could later be incorporated into lead compounds for novel antibiotic drug discovery. One of P. …

Applications In Opioid Analysis With Faims Through Control Of Vapor Phase Solvent Modifiers, Nathan Grimes

USF Tampa Graduate Theses and Dissertations

Field Asymmetric Ion Mobility Spectrometry (FAIMS), often coupled with mass spectrometry (MS), offers rapid analytical ion filtration, useful in reducing matrix interference and differentiating isomeric compounds. This study focuses on augmenting FAIMS-MS analyses through the incorporation of gas phase solvents, or "modifiers," inducing dynamic microsolvation, a particularly potent method of analysis enhancement.

Initially, the research utilized a bubbler-based system, incorporating a humidity sensor, improving modifier concentration control when using water. Our application in opioid detection and differentiation revealed considerable advancements. Notably, an increased peak capacity in an opioid mixture and successful separation of the isobaric opioid pair, alfentanil and ortho-isopropyl …

Identification Of Different Hair Dyes In Dyed Hair Using Attenuated Total Reflectance (Atr Ft-Ir), Surface Enhancing Raman Spectroscopy (Sers) Techniques, Nicholas Lovera

Student Theses

This investigation compares the ability of Attenuated Total Reflection Fourier Transfer Infrared Spectroscopy (ATR FT-IR) and Surface Enhance Raman Spectroscopy (SERS) to identify and differentiate different hair dye brands on dyed hair samples. Hair is a common type of trace evidence found at crime scenes and can provide numerous information through forensic hair analysis. Cosmetic hair treatment such as dying the hair different colors has grown and became popular, thus it can be a very common type of trace evidence. This study can provide a forensic scientist an additional method for analyzing dyed hair samples. The goal was to compare …

Enhanced Methods In Forensic Mass Spectrometry For Targeted And Untargeted Drug Analysis, Dina M. Swanson

USF Tampa Graduate Theses and Dissertations

Forensic science has long used mass spectrometry for the analysis of drugsand metabolites. Traditionally, screening methods consisted of color tests or immunoassay and confirmation methods used gas chromatography with mass spectrometry, which was considered the gold standard for identification. In the last several decades, advances in liquid chromatography with mass spectrometry (LCMS) have brought this technology to the forefront of forensic drug identification. Drug identification in forensic drug chemistry and forensic toxicology has become increasingly challenging due to the rapid increase in illicit drug analogs including novel opioids such as fentanyl analogs. Traditional screening methodologies are often unable to identify …

Sers For The Detection Of Trace Materials, Omari Kirkland

Dissertations, Theses, and Capstone Projects

In this dissertation are presented three projects that contribute to the body of research on SERS in the forensic, heritage, and semiconductor fields. The first project, Charge-Transfer mapping on GaN/Ag, a silver-decorated nanopillar semiconductor substrate fabricated from the GaN is used with the Raman probe Rhodamine 6 G (R6G) to map the effect of the nanofeatures on the CT resonance. The second project, in collaboration with Marco Leona from the Metropolitan Museum of Art, explores the use of AgNIFs to identify colorants used on textile fiber samples from four 19th century works of Japanese art. The final project analyzes the …

Advances In Structure Elucidation Of Small Molecules And Peptides By Nuclear Magnetic Resonance Spectroscopy And Mass Spectrometry, Ryan D. Cohen

Seton Hall University Dissertations and Theses (ETDs)

This dissertation reports on improvements in nuclear magnetic resonance (NMR) and mass spectrometry (MS) structure determination methods of organic compounds, with particular focus on challenging cyclic peptides. A recent and important innovation in NMR spectroscopy is the combination of theoretical property predictions, such as chemical shifts, using density functional theory (DFT) to aid in challenging NMR structure assignments, such as determination of regio- and stereo-configurations. In the first part of this thesis, a comprehensive benchmark study of DFT chemical shift prediction methods was performed using experimental NMR data collected from 50 well curated compounds, which was referred to as the …

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …

Synthesizing, Purifying, And Characterizing Molten Chloride Salts, Phillip W. Halstenberg

Doctoral Dissertations

Molten chloride salts have vast potential as heat transfer fluids with both nuclear and concentrated solar power applications. For application in energy systems, the characteristics that govern these systems must be well understood. This work focuses on inorganic molten chloride salts with a special emphasis on the experimental aspect of chemical research. Chapter 2 covers the synthetic approaches for the formation of molten chloride mixtures. Many salts can be purchased from industrial suppliers, but most must be purified therefore, Chapter 3 evaluates various methodology developed for removal of impurities in salt mixtures. Once the salt of proper content and purity …

Mechanochemical Synthesis Of Task-Specific Conjugated Porous Networks Towards Enhanced Energy Storage, Juntian Fan

Doctoral Dissertations

Conjugated scaffolds with high electronic conductivity, high surface area, etc. are promising materials for diverse technological applications, especially in the electrochemical field. However, the current synthesis methods are still limited to the traditional solution-based method or the ionothermal method, which always require an inert atmosphere shield, large amounts of organic solvents, noble catalysts, long reaction time up to days, and high temperatures, etc. Therefore, there is a common goal of developing conjugated scaffolds through facile, green, straightforward pathways. Mechanochemistry, which is an efficient, sustainable, solvent-free methodology, could provide a unique reaction environment to synthesize this kind of functionalized materials, resulting …