Other Chemistry Commons^™

Aptamer-Based Voltammetric Biosensing For The Detection Of Codeine And Fentanyl In Sweat And Saliva, Rosa Lashantez Cromartie

FIU Electronic Theses and Dissertations

Despite the many governmental and medicinal restrictions created to combat the opioid epidemic in the United States, opioid abuse and overdose rates continue to rise. The development of an aptamer-based voltammetric sensor and biosensor is described in this dissertation. The aim was to develop a low-cost, sensitive, and specific aptamer-based sensor for on-site, label-free determination of codeine and fentanyl in biological fluids. To do this, the surfaces of screen-printed carbon electrodes (SPCE) were modified with gold nanoparticles (AuNPs), followed by the addition of single-stranded DNA aptamers. These were covalently bound to the electrode surface. Operations of the sensors were collected …

Purine Nucleosides Modified At C8 Or C2 Position With (Β-Halo)Vinylsulfone And Β-Ketosulfone Reactive Groups And Their Incorporation Into Dna: Synthesis Of The Organoarsenical Antibiotic Arsinothricin And Polyaromatic Hydrocarbons, Md Abu Hasan Howlader

FIU Electronic Theses and Dissertations

Modified nucleosides gained great attention as potential anticancer and antiviral therapeutics. In this dissertation, synthesis and reactivity of (β-iodovinyl)sulfone and β-ketosulfone groups incorporated into purine nucleosides at C8 or C2 positions and DNA incorporation of their 5' triphosphates have been developed. Moreover, synthesis of novel antibiotic arsinothricin (AST) as well as polycyclic aromatic hydrocarbons (PAHs) have been discussed. The 8-(1-iodo-2-tosylvinyl)-2'-deoxyadenosine and 8-(1-Iodo-2-tosylvinyl)adenosine were synthesized employing iodovinylsulfonation of 8-ethynyl precursors with TsNa/I₂/NaOAc. The 8-(β-iodovinyl)sulfonyl-2'-deoxyguanosine was prepared via radical mediated iodovinylsulfonation of 8-ethynyl-2'-deoxyguanosine with TsNHNH₂/KI/(BzO)₂. Conformationally different C2 substituted isomeric adenosine analogues were prepared by iodovinylsulfonation …

The Development Of A Surface Enhanced Raman Spectroscopy Method For The Detection Of Synthetic Cannabinoids In Urine, Thaddeus Mostowtt

FIU Electronic Theses and Dissertations

The use and abuse of synthetic cannabinoids has increased significantly in recent years due to their easy access and growing popularity. Despite having more known drugs become illegal, new synthetic versions of these drugs are being made that have not yet been recognized or classified as illegal substances. Therefore, standard methods may not be able to detect these drugs.

The most common method of screening detection for drugs of abuse in biological samples is the immunoassay. However, the immunoassay method presents some disadvantages, particularly for newly synthesized compounds. More advanced methods have also been used, such as LC-MS; however, these …

Systematic Comparison Of Pre-Treatment Parameters In Forensic Hair Analysis And Investigating Hair-Drug Interactions, Jennett Chenevert Aijala

FIU Electronic Theses and Dissertations

Forensic toxicological analysis for the purposes of protecting human health and supporting criminal justice activities can be achieved, in part, by means of analysis of human head hair for detection of abused substances. Hair is considered an alternative sample matrix (compared to blood and urine) because of persistent interpretive challenges caused by a lack of standardization in analytical approaches and poor understanding of the biases resulting from physicochemical interactions between major hair components (e.g., melanin) and drugs of abuse. Some of the uncertainty regarding optimal techniques for the pre-treatment of hair specimens results from the unknown nature of the …

An Investigation Into The Adduct Forming Potential Of Drugs Of Abuse With Peptides And Proteins, Richard Allen Gilliland

FIU Electronic Theses and Dissertations

Hemoglobin and serum albumin, two prevalent proteins in human blood, contain unbound cysteine thiol moieties, creating a nucleophilic site with the potential for covalent modification by reactive chemical species. These covalent modifications, called “adducts”, are stable entities that accumulate during acute and chronic exposure and remain covalently bound for the life-span of the protein. Despite their current use as exposure markers for a variety of compounds, the use of adducts in assessing exposure to drugs of abuse has not yet been explored. The goal of this work was to examine the in vitro adduct forming capability of selected drugs of …

Forensic Toxicological Screening And Confirmation Of 800+ Novel Psychoactive Substances By Lc-Qtof-Ms And 2d-Lc Analysis, Melanie N. Eckberg

FIU Electronic Theses and Dissertations

Novel psychoactive substances (NPS) represent a great challenge to toxicologists due to the ability of illicit drug manufacturers to alter NPS chemical structures quickly and with ease to circumvent legislation regulating their use. Each time a new structure is introduced, there is a possibility that it has not been previously recorded in law enforcement or scientific databases. Many toxicology laboratories use targeted analytical methods that rely on libraries of known compounds to identify drugs in samples. However, these libraries do not include large numbers of NPS which could result in non-identification or detection.

High-resolution mass spectrometry (HRMS) has been suggested …

Applications Of Paper Microfluidic Systems In The Field Detection Of Drugs Of Abuse, Ling Wang

FIU Electronic Theses and Dissertations

Over the years, colorimetric reagents and immunology have been widely used in screening tests for illicit drugs; however, the test kits are not always convenient for field use and often require the user to mix and develop a specific set of reagents. In our project, we have been working on alternative platforms based on paper microfluidic devices (uPADs) for field testing. These devices utilize wax channels printed on paper to direct the analyte towards a specific set of chemical reagents. Using the procedure, we have developed a six-channel chip that adapts known colorimetric reagents targeting cocaine, opiates, amphetamines and ketamine …

Qualitative Detection Of Selected Designer Drugs And Relevant Metabolites In Environmental Water Samples, Marley Pruyn

FIU Electronic Theses and Dissertations

Designer drugs are compounds which have been synthetically derived from illicit drugs. After consumption, drugs and their metabolites are introduced into the sewage water which is treated and disposed into the environment. A combined target, suspect and non-target workflow was created to detect designer drugs in environmental water samples. Multiple water samples were spiked with an unknown mixture of drugs and metabolites to assess the efficiency of the method. Samples were collected from sewage influent and effluent pipes, downstream from a sewage outfall and reclaimed water. Analysis was conducted with high resolution MS using the QExactive Orbitrap. Screening was performed …

Determination Of Human Scent Biomarkers For Race, Ethnicity And Gender, Lauren J. Colόn Crespo

FIU Electronic Theses and Dissertations

Human scent has been the focal point of diverse scientific interests and research initiatives for the past several years. The knowledge gained about its composition has favored the advancement of multiple disciplines, and promoted the development of a wide variety of applications. Among these applications is the use of human scent as a resource for Forensic investigations, where scent profiles are often used as evidence to associate individuals to the scene of a crime. The characteristic nature of individual human scent has enabled this type of evidence to be used as a biometric tool for the differentiation of subjects. Nevertheless, …

Mangiferin As A Biomarker For Mango Anthracnose Resistance, Herma Pierre

FIU Electronic Theses and Dissertations

Mangos (Mangifera indica L.) are tropical/subtropical fruits belonging to the plant family Anacardiaceae. Anthracnose is the most deleterious disease of mango both in the field and during postharvest handling. It is most commonly caused by the Colletotrichum gloeosporioides complex. Mangiferin, a xanthanoid compound found in at least twelve plant families worldwide (Luo et al., 2012), is present in large amounts of the leaves and edible mangos. Even though this compound plays a pivotal role in the plant’s defense against biotic and abiotic stressors, no correlations been made between the compound and mango anthracnose resistance.

Mangos were collected, grouped …

Analysis Of Synthetic Cannabinoids By Direct Analysis In Real Time Quadrupole Time-Of-Flight Mass Spectrometry And Gas Chromatography Quadrupole Time-Of-Flight Mass Spectrometry, Tyler S. Torbet

FIU Electronic Theses and Dissertations

The aim of this study was to investigate the utility of direct analysis in real time quadrupole time-of-flight mass spectrometry and gas chromatography quadrupole time-of-flight mass spectrometry in the analysis of 162 different synthetic cannabinoids. Direct analysis in real time quadrupole time-of-flight mass spectrometry is shown to be a rapid and accurate analytical method for synthetic cannabinoids. Spectra can be generated with less than 1.5 ng of the drug in under a minute and be successfully searched against previously generated ESI-QTOF libraries in most cases (118/130 drugs tested) as well as can also be applied to the identification of synthetic …

Development Of A Surface-Enhanced Raman Spectroscopy Method For The Detection Of Benzodiazepines In Urine, Erika L. Doctor

FIU Electronic Theses and Dissertations

Benzodiazepines are among the most prescribed compounds for anti-anxiety and are present in many toxicological screens. These drugs are also prominent in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to their potency, a low dose of these compounds is often administered to victims; therefore, the target detection limit for these compounds in biological samples is 10 ng/mL. Currently these compounds are predominantly analyzed using immunoassay techniques; however more specific screening methods are needed.

The goal of this dissertation was to develop a rapid, specific screening technique for benzodiazepines in urine samples …

Development Of Presumptive And Confirmatory Analytical Methods For The Simultaneous Detection Of Multiple Improvised Explosives, Kelley L. Peters

FIU Electronic Theses and Dissertations

In recent years, there has been a dramatic increase in the use of improvised explosive devices (IEDs) due to ease of synthesis and improved controls placed on commercial/military explosives. Commonly used materials for IED preparations include fertilizers and industrial chemicals containing oxidizers such as ClO₃^-, ClO₄^-, and NO₃^-, as well as other less stable compounds, such as peroxides. Due to these materials having a wide range of volatility, polarity, and composition, detection can be challenging, increasing the amount of time before any analytical information on the identity of the explosive can …

Investigating The In Vitro Oxidative Folding Pathways Of Bovine Pancreatic Trypsin Inhibitor (Bpti), Yingsong Wang

FIU Electronic Theses and Dissertations

The oxidative folding pathway of the disulfide containing protein bovine pancreatic trypsin inhibitor (BPTI) was one of the first to be elucidated and has served as a basis for understanding the folding pathways of other proteins. During the oxidative folding of reduced BPTI, two intermediates (N' and N*) accumulate in significant amounts and act as kinetic traps. Both N' and N* bury their two remaining free thiols in their hydrophobic cores, which inhibits further oxidation. Historically, the rate limiting step was considered to be the intramolecular rearrangements of N' and N* to another intermediate with two free thiols, N^{SH …}

Method Development For The Analysis Of Smokeless Powders And Organic Gunshot Residue By Ultra Performance Liquid Chromatography With Tandem Mass Spectrometry, Jennifer L. Thomas

FIU Electronic Theses and Dissertations

The goal of this project was to develop a rapid separation and detection method for analyzing organic compounds in smokeless powders and then test its applicability on gunshot residue (GSR) samples. In this project, a total of 20 common smokeless powder additives and their decomposition products were separated by ultra performance liquid chromatography (UPLC) and confirmed by tandem mass spectrometry (MS/MS) using multiple reaction monitoring mode (MRM). Some of the targeted compounds included diphenylamines, centralites, nitrotoluenes, nitroglycerin, and various phthalates. The compounds were ionized in the MS source using simultaneous positive and negative electrospray ionization (ESI) with negative atmospheric pressure …

Development Of A Dynamic Headspace Concentration Technique For The Non-Contact Sampling Of Human Odor Samples And The Creation Of Canine Training Aids, Lauryn E. Degreeff

FIU Electronic Theses and Dissertations

Human scent and human remains detection canines are used to locate living or deceased humans under many circumstances. Human scent canines locate individual humans on the basis of their unique scent profile, while human remains detection canines locate the general scent of decomposing human remains. Scent evidence is often collected by law enforcement agencies using a Scent Transfer Unit, a dynamic headspace concentration device. The goals of this research were to evaluate the STU-100 for the collection of human scent samples, and to apply this method to the collection of living and deceased human samples, and to the creation of …

Development Of Microsatellite Markers In Cannabis Sativa For Fingerprinting And Genetic Relatedness Analyses, Hussain J. Al-Ghanim

FIU Electronic Theses and Dissertations

Microsatellite markers were developed for Cannabis sativa L. (marijuana) to estimate the level of polymorphism, usefulness for DNA typing (genotype identification), and to measure the genetic relationships between the different plants. Twelve different oligonucleotide probes were used to screen an enriched microsatellite library of Cannabis sativa in which 49% of the clones contained microsatellite sequences. Characterization of microsatellite loci in Cannabis revealed that GA/CT was the most abundant class of isolated microsatellites representing 50% overall. Eleven polymorphic SSR markers were developed, derived from dinucleotide motifs and eight from trinucleotide motifs. A total of 52 alleles were detected averaging 4.7 alleles/locus. …