Analytical Chemistry Commons^™

Spheroid-3d And Monolayer-2d Intestinal Electrochemical Biosensor For Toxicity/Viability Testing: Applications In Drug Screening, Food Safety, And Environmental Pollutant Analysis, Evangelia Flampouri, Shahzad Imar, Kieran O'Connell, Baljit Singh

Articles

The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable …

Application Of Analytical Techniques In Food Product Development, Sonali R. Pandey

Electronic Theses and Dissertations

Products are analyzed in major sectors of food industry to meet regulatory standards, food safety, quality control, and research and development. Analytical and extraction techniques have been applied for simultaneous investigation of multiple product characteristics. Food analysis faces critical challenges due to the complex composition of food, leading to matrix effects that result in loss of accuracy and reliability. The analytical techniques require an efficient sample preparation to avoid or minimize matrix effects. Solid-phase extraction has been widely used to address this issue. In this dissertation, the aim is to apply analytical techniques in food product development. To accomplish this, …

Evaluation Of Fingerprint Content For Forensic Crime Scene Analysis And Drug Metabolite Detection, Erica Kathryn Brunelle

Legacy Theses & Dissertations (2009 - 2024)

With respect to criminal investigations, one key piece of evidence that often gets overlooked are fingerprints. For years, fingerprint samples have been believed to be useful only for matching purposes using their unique ridges, shapes, and sizes. With the rapid growth of forensic science, it has become evident that the development of fingerprint analysis has been stagnant. The traditional approach has been advantageous for the identification of many individuals; however, many fingerprint samples have been labeled “unusable” due to smudging, smearing, or any one of a myriad of reasons that could cause inconclusive matches. These samples can, however, still be …

Accumulation And Spatial Distribution Of Lead And Other Trace Elements In Keratinized Tissues : Investigations Based On Analytical Atomic Spectrometry, Mina W. Tehrani

Legacy Theses & Dissertations (2009 - 2024)

Human biomonitoring for toxic metals such as lead (Pb) provides information about absorbed dose from all exposure routes, and is critical for identifying exposed individuals and assessing health risks. Blood Pb and bone Pb are the primary validated biomarkers for assessing short-term and historical Pb exposures, respectively, while non-traditional matrices, including keratinized tissues, can provide complementary exposure information. Hard keratinized tissues – including hair, nails, hooves, and horns – grow incrementally, potentially preserving chemical exposure histories over a span of days to years. Analytical limitations and poor interlaboratory reproducibility, however, have led to debate around the use of human nails …

Anthocyanin Stability In Food Products Made With Freeze-Dried Blueberry Powder, Samantha R. Findley, Luke Howard

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

This study evaluated the stability of anthocyanins in six blueberry products (gummy, graham bar, oatmeal bar, rice krispy bar, ice pop and juice) prepared with freeze-dried wild blueberry powder during processing and over eight weeks storage. Total anthocyanins were determined by HPLC before processing and at day 0 and 2, 4, 6, and 8 weeks of storage. Thermal processing of gummy and graham bar products resulted in losses of anthocyanins (50 and 31%, respectively). An eight-week storage time also resulted in a decrease in anthocyanins (7 to 51%) in products stored at ambient temperature. The ice pop, which was stored …

Electrochemical Detection Of Fentanyl Using Screen-Printed Carbon Electrodes With Confirmatory Analysis Of Fentanyl And Its Analogs In Oral Fluid Using Liquid Chromatography-Tandem Mass Spectrometry, Colby E. Ott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Utilizing screen-printed carbon electrodes (SPCEs), a fast, simple, and sensitive approach toward the detection, identification, and quasi-quantitation of fentanyl was achieved both in an electrochemical cell and as a drop on the electrode surface. Electro-oxidation of fentanyl at the electrode was demonstrated using adsorptive stripping square-wave voltammetry between -0.5 V and +1.6 V with 100 mM Tris-HCl buffer at pH 8.5 as supporting electrolyte. Parameter optimization was conducted during method development to include supporting electrolyte and pH, electrochemical technique, pre-treatment and equilibration time, and various surface modifications. The simplest method utilizing an unmodified SPCE was determined to be appropriate for …

Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this work we demonstrate the power of compound-specific isotope analysis (CSIA) to analyze proteinaceous biological materials in three distinct forensic applications, including: 1) linking necrophagous blow flies in different life stages to their primary carrion diet; 2) identifying the harvesting area of oysters for food authentication purposes; and 3) the ability to predict biometric traits about humans from their hair.

In the first application, we measured the amino-acid-level fractionation that occurs at each major life stage of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) blow flies. Adult blow flies oviposited on raw pork muscle, beef muscle, or chicken liver. Larvae, pupae …

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …

Rapid Analysis Of Magnesium In Infant Formula Powder Using Laser-Induced Breakdown Spectroscopy, Maria Markiewicz-Keszycka, Ming Zhao, Xavier Cama-Moncunill, Toufic El Arnaout, Dana Becker, Colm O'Donnell, P. J. Cullen, Carl Sullivan, Maria Piedad Casado-Gavalda

Articles

Laser-induced breakdown spectroscopy (LIBS) was investigated to determine magnesium (Mg) content in infant formula powder. To predict Mg content in the range established by the Codex Alimentarius, a partial least squares regression (PLSR) model was developed using a calibration data set (n = 30) based on full cross-validation and validated using an independent validation data set (n = 21). The prediction model performance was evaluated using the regression coefficients of determination (Rcv2 = 0.94 and Rp2 = 0.85) with the root mean square errors on cross-validation and prediction (RMSECV = 60 mg kg−1 and RMSEP = 80 mg kg−1). The …

Near-Infrared Fluorescent Probes For Sensitive Determination Of Lysosomal & Mitochondrial Ph In Live Cells, Wafa Mazi

Dissertations, Master's Theses and Master's Reports

Varied intracellular pH levels are critical for various physiological processes such as enzymatic activity, cell proliferation and apoptosis, ion transport, and muscle contraction. Cellular compartments, like lysosomes, must retain an acidic environment (pH ~ 4.5) to activate hydrolytic enzymes necessary for the breakdown of large biomolecules. Another cellular organelle, the mitochondria, provides the cell with energy and must retain an alkalis environment (pH ~ 8.0) for proper function. Substantial lysosomal and mitochondrial pH deviation is associated with cellular dysfunction and disease. Therefore, the precise detection of lysosomal and mitochondrial pH is essential to provide a better understanding of cellular physiological …

Consumption Profiles Of Illicit And Neuropsychiatric Drugs In Urban And Rural Communities In Kentucky Using Sewage Epidemiology, Tara Croft, Katelyn Foppe, Rhiannon Huffines, Bikram Subedi

Posters-at-the-Capitol

The drug overdose deaths in the USA increased by ~20% from 2015 to 2016 to the total >63,600 drug overdose deaths in 2016. Kentucky is among the highest rate of drug overdose death states in the USA. The current estimates of the prevalence of substance abuse are based on the self-reported surveys, overdose/toxicological reports, and drug-related crime statistics. Survey-based conventional approaches are not only cost and time-intensive but also underestimate the actual consumption of drugs. As “wastewater never lie,” the drug residues in raw wastewater collected from the centralized wastewater treatment plants were utilized to determine the consumption rate of …

Developing A New Sensing Technology For Double-Stranded Dna Detection Utilizing Engineered Zinc Finger Proteins And Nanomaterials, Dat Thinh Ha

Masters Theses & Specialist Projects

A specific double-stranded DNA sensing system is of great interest for diagnostic and other biomedical applications. Zinc finger domains, which recognize double-stranded DNA, can be engineered to form custom DNA-binding proteins for recognition of specific DNA sequences. As a proof of concept, a sequence-enabled reassembly of TEM-1 β- lactamase system (SEER-LAC) was previously demonstrated to develop zinc finger protein (ZFP) arrays for the detection of a double-stranded bacterial DNA sequence. Here, we implemented the SEER-LAC system to demonstrate the direct detection of pathogenspecific DNA sequences present in E. coli O157:H7 on the lab-on-a chip. ZFPs customdesigned to detect shiga toxin …

Tof-Sims Analysis Of Plant Seed Interactions With Plant Growth-Promoting Bacteria, Tammy Pheuphong, Rachel Komorek, Xiao-Ying Yu

STAR Program Research Presentations

The use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) in plant biology is a relatively unexplored and quickly developing field. The majority of research in plant SIMS involves the application of ToF-SIMS to study dried wood tissues, and only a handful of studies apply SIMS on plant stems, roots, and/or seeds. Our project provides a brief description and review of previous work using SIMS on plant stems, roots, and/or seeds, along with an emphasis on the sample preparation in each study. Additionally, the use of Brachypodium distachyon (Brachypodium) as a model system for research on grasses has also become more …

Manganese Oxide/Hemin-Functionalized Graphene As A Platform For Peroxynitrite Sensing, Haitham F. Kalil, Shaimaa Maher, Tiyash Bose, Mekki Bayachou

Chemistry Faculty Publications

Peroxynitrite (ONOO−, PON) is a powerful oxidizing agent generated in vivo by the diffusion-limited reaction of nitric oxide (NO) and superoxide (O₂˙⁻) radicals. Under oxidative stress, cumulated peroxynitrite levels are associated with chronic inflammatory disorders and other pathophysiological conditions. The accurate detection of peroxynitrite in biological systems is important, not only to understand the genesis and development of diseases, but also to explore and design potential therapeutics. Herein, a manganese oxide/hemin-modified graphene interface is explored as a platform for peroxynitrite amperometric detection. Hemin-functionalized reduced graphene oxide was further modified with manganese oxide nanoparticles to provide a …

Development Of Rapid, Homogeneous Assay For Investigating Isopeptide Bond Formation Using Fluorescence Polarization/Depolarization Measurements, Samuel Patricc Kasson

Graduate Theses/Dissertations

Autocatalytic intramolecular isopeptide bonds have been found in nature in certain gram-positive bacterial pilus structures. Recently, splitting of these domains that are capable of autocatalytic intramolecular isopeptide bond formation have been applied to create stable, selective, bio-orthogonal Catcher/Tag systems. The CnaB2 domain found in the FbaB pilus structure of Streptococcus pyogenes, has yielded the Catcher/Tag, Protein/Peptide systems termed SpyCatchter and SpyTag. Recent study has focused on tag optimization, stability and bio-orthogonality evaluation, along with applications in bioconjugation. I have recombinantly expressed SpyCatcher and SpyTag-fused proteins in E.coli, and conjugated them to fluorescent probes in order for use in fluorescence polarization/depolarization …

Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor

Electronic Theses and Dissertations

Metabolomics, the study of small molecules in biological systems, has enjoyed great success in enabling researchers to examine disease-associated metabolic dysregulation and has been utilized for the discovery biomarkers of disease and phenotypic states. In spite of recent technological advances in the analytical platforms utilized in metabolomics and the proliferation of tools for the analysis of metabolomics data, significant challenges in metabolomics data analyses remain. In this dissertation, we present three of these challenges and Bayesian methodological solutions for each. In the first part we develop a new methodology to serve a basis for making higher order inferences in metabolomics, …

The Effects Of Cold Plasma Treatment On Sweet Basil (Ocimum Basilicum), Sauvelson Auguste

Seton Hall University Dissertations and Theses (ETDs)

The study discussed herein looks both to continue and to expand upon previous work conducted here at Seton Hall University, which investigated the effect of cold plasma processing on sweet basil and their essential oils. It was found that the application of cold plasma treatment increases plant growth and eugenol concentration, which is an essential oil component and one of the potential natural antioxidants used in food preservation. In this study, we considered methods for increasing the production and harvesting of plants that produce essential oils such as sweet basil (Ocimum basilicum). The study also incorporated more controls …

Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols of variable composition, size, and shape are associated with public health concerns as well as with light-particle interactions that play a role in the energy balance of the atmosphere. Photochemical reactions of 2-oxocarboxylic acids in the aqueous phase are now known to contribute to the total secondary organic aerosol (SOA) budget. This work explores the cross reaction of glyoxylic acid (GA) and pyruvic acid (PA) in water, the two most abundant 2-oxocarboxylic acids in the atmosphere, under solar irradiation and dark thermal aging steps. During irradiation, PA and GA are excited and initiate proton-coupled electron transfer or hydrogen abstraction …

Advances In Amino Acid Analysis For Marine Related Matrices And Its Application To Coastal Shelf Settings In The Canadian Arctic, Rachel M. Mcmahon

OES Theses and Dissertations

Amino acids comprise up to 50% of organic matter in cellular material and are a major fraction of oceanic organic carbon. Amino acids are also considered highly labile during organic matter recycling, making them useful proxies for organic carbon cycling. Nevertheless, analysis of individual amino acids has been burdened by lengthy derivatization and complex analysis since the 1950s. In this thesis, I describe the modification of advanced analytical techniques, developed in the biomedical field, for analysis of marine matrices which allow the determination of at least 40 amino acids without the need for lengthy sample preparation and derivatization, twice the …

Quantitative Proteomics To Support Translational Cancer Research, Melissa Hoffman

USF Tampa Graduate Theses and Dissertations

Altered signaling pathways, which are mediated by post-translational modifications and changes in protein expression levels, are key regulators of cancer initiation, progression, and therapeutic escape. Many aspects of cancer progression, including early carcinogenesis and immediate response to drug treatment, are beyond the scope of genetic profiling and non-invasive monitoring techniques. Global protein profiling of cancer cell line models, tumor tissues, and biofluids (e.g. serum or urine) using mass spectrometry-based proteomics produces novel biological insights, which support improved patient outcomes. Recent technological advances resulting in next-generation mass spectrometry instrumentation and improved bioinformatics workflows have led to unprecedented measurement reproducibility as well …

Eating Crickets? Nutrient Mineral Content Of Two Cricket Species And Chapul Cricket Protein Bars Using Mp-Aes, Nathan Hopkins

Student Scholar Showcase

Global agriculture is beset by numerous challenges which must be surmounted to feed a developing world, from combating climate change to the cultivation of sustainable food products. This, in addition to protein and nutrient deficiencies in the developing world, makes considering alternative protein sources, such as a crickets, an attractive option. Crickets use a fraction of the land and water that protein sources like beef cattle do, and can be cultivated in urban environments in stacked boxes. This research investigation aims to quantify the nutrient mineral content (Iron, Sodium, Potassium, Calcium, and Magnesium) of two cricket species (Acheta domesticus …

Analysis Of Metallic Components Of Gsr From Various Types Of Ammunition And Firearms Utilizing An Sem-Edx, Jenna A. Campbell

Graduate Student Research Symposium

Gunshot residue (GSR) is a chemical reaction that occurs when a firearm is discharged, which emits a cloud of gases from the barrel of the gun. It consists of both the burned and unburned propellant and primer components. These components are either organic or inorganic in nature, respectively. The organic components are located in the gunpowder part of the bullet, while the inorganic components are located in the primer part of the bullet. The primer consists of lead, barium, and antimony. These elements are considered heavy metals. Additionally, lead, barium, and antimony are the three key elements found in the …

Legacy Contaminants In The Northern Gulf Of Mexico Shelf, Jessica N. Landry

LSU Master's Theses

The Mississippi River watershed is the third largest in the world and drains from 31 states in the United States. Due to its route through the U.S., it passes through hundreds of EPA labeled Superfund sites as well as agricultural and suburban watersheds. These sites are known to have historical chemical contamination, and as a result chemicals can be transported by runoff down the Mississippi River into the Gulf of Mexico where their ultimate fate is unknown. Organochlorine chemicals are known to be persistent and are found in agricultural land as well as US EPA Superfund sites, especially DDT, PCBs, …

The Therapeutic Potential Of Natural Products From Vaccinium Berries For Viral And Lung Diseases Through An Improved Lc-Ms-Based Chemometric Approach, Vanya I. Petrova

Dissertations, Theses, and Capstone Projects

Smoking is a global epidemic that creates serious health and economic burden. It is the primary, preventative factor for the majority of causes of death worldwide. Analysis of publicly available data revealed that smoking prevalence rates among the youth in developing countries, especially in Bulgaria, are alarmingly high. The Bulgarian population has one of the highest percentages of smokers and the second highest rate among teenage girls. Consequently, chronic diseases affected by smoking, such as chronic obstructive pulmonary disorder (COPD), have been increasing there in the last five years. Poland, on the other hand, is an exemplary outlier for the …

Quantitative Analysis Of Bleomycin In Rat Plasma By Lc-Ms/Ms, Huawen Li

ETD Archive

Bleomycin is the most commonly used compound in its group of antineoplastic drugs. It works on tumor cells by single and double stranded DNA cleavage after its activation, in which it blocks tumor cells’ DNA replication or transcription activities to inhibit tumor cells’ growth. Bleomycin sulfate (Blenoxane) is the most popular preparation used in clinical research, and contains Bleomycin fractions of A2 and B2, which causes difficulties in quantitative analysis. This work uses the metal chelating property of Bleomycin as an advantage to simplify and improve sensitivity of existing quantitative methods. Copper was spiked in excess to plasma samples, followed …

Development Of Multi-Class Analytical Methods For Agrochemical Contaminants, Sarah Tuck

Theses

In this project, cost-effective multi-class analytical methods were developed to detect a range of antiparasitic, feed additive and pesticide substances in foodstuffs of animal origin. These substances have the potential to enter the food chain through their occurrence as residues either through the animals themselves or other routes e.g. contamination. To ensure the continued safety of food destined for human consumption regulatory control limits have been established for permitted levels of these residues in foods of animal origin. Despite these controls the continued monitoring of foodstuffs is necessary to ensure these limits are not breached and that substances are not …

Technology Development For Detection Of Circulating Disease Biomarkers From Liquid Biopsies Using Multifunctional Nanomaterials, Mustafa Balcioglu

Legacy Theses & Dissertations (2009 - 2024)

Despite the advance health care, devastating health conditions such as cancer and infectious diseases that affect populations worldwide are too often not diagnosed until morbid symptoms become apparent in the late phase. Obtaining an early and accurate diagnosis that reveal a hidden lethal threat before the disease becomes complicated may dramatically reduce the severity of its impact on the patient’s life and increase the probability of survival. For example, in the case of ovarian cancer, which is the fifth most common malignancy and the fifth leading cause of cancer mortality in women in the US, the 5-year relative survival is …

Integrated Immunoassays On Paper/Polymer Hybrid Microfluidic Devices For Low-Cost Detection Of Disease Biomarkers, Sanjay Sharma Timilsina

Open Access Theses & Dissertations

Infectious diseases and cancers have been the major cause of global death and disability causing a significant impact on global health and economies. Enzyme-linked immunosorbent assay (ELISA) is one of the most widely used laboratory diagnostic methods for infectious diseases and cancer. ELISA detects proteins based on their binding to immobilized antibodies or antigen. Even though most ELISAs performed today in 96-well plates are well suited for high throughput assays, performing ELISA in low-resource settings is limited by several factors, such as long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we have developed multiple simple, miniaturized …

Quantitation Without Calibration: Response Profile As An Indicator Of Target Amount, Mrittika Debnath

Graduate Research Theses & Dissertations

Quantitative assessment of biomarkers is essential in numerous contexts from decision-making in clinical situations to food quality monitoring to the interpretation of life-science research findings. However, appropriate quantitation techniques are not as widely addressed as detection methods. One of the major challenges in biomarker’s quantitation is the need to have a calibration for correlating a measured signal to a target amount. The step complicates the methodologies and makes them less sustainable. In this work, we addressed the issue via a new strategy: relying on the position of response profile rather than absolute signal for assessment of a target nucleic acid’s …

Applications Of Cell-Derived Vesicles: From Single Molecule Studies To Drug Delivery, Faruk H. Moonschi

Theses and Dissertations--Chemistry

Single molecule studies can provide information of biological molecules which otherwise is lost in ensemble studies. A wide variety of fluorescence-based techniques are utilized for single molecule studies. While these tools have been widely applied for imaging soluble proteins, single molecule studies of transmembrane proteins are much more complicated. A primary reason for this is that, unlike membrane proteins, soluble proteins can be easily isolated from the cellular environment. One approach to isolate membrane proteins into single molecule level involves a very low label expression of the protein in cells. However, cells generate background fluorescence leading to a very low …