Chemistry Commons^™

Synthesis, X-Ray Structures, Electronic Properties, And O2/No Reactivities Of Thiol Dioxygenase Active-Site Models, Anne A. Fischer, Nuru Stracey, Sergey V. Lindeman, Thomas C. Brunold, Adam T. Fiedler

Chemistry Faculty Research and Publications

Mononuclear non-heme iron complexes that serve as structural and functional mimics of the thiol dioxygenases (TDOs), cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO), have been prepared and characterized with crystallographic, spectroscopic, kinetic, and computational methods. The high-spin Fe(II) complexes feature the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (^Ph2TIP) ligand that replicates the three histidine (3His) triad of the TDO active sites. Further coordination with bidentate l-cysteine ethyl ester (CysOEt) or cysteamine (CysAm) anions yielded five-coordinate (5C) complexes that resemble the substrate-bound forms of CDO and ADO, respectively. Detailed electronic-structure descriptions of the [Fe(^Ph2TIP)(L_S,N)]BPh₄ complexes, where L …

‘A Novel Kaposi’S Sarcoma Therapy:’ Plasmonic Nanoparticles For Light-Mediated Drug Delivery, Blake Peter Kruger

Honors Theses

No abstract provided.

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO₂ photocatalysts for splitting water (4) and reducing CO₂ (5) to form useful chemical feedstock such as H₂, CO and CH₄, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …

Graphene Quantum Dots Electrochemistry And Development Of Sensitive Electrochemical Biosensor [Hybrid Poster 1-B], Tyler Smith, Alexander Banaszak

Posters-at-the-Capitol

Graphene quantum dots (GQDs) are zero-dimensional material derived from graphene derivatives with characteristics from the structure of graphene with quantum confinement and edge effects possessing unique properties. Intense research activity in GQDs is attributed to their novel physical-chemical phenomena arising from the sp²-bonded carbon core surrounded with edge functional moieties. In this work, GQDs of optimal 5-7 nm size are investigated for their fundamental electrochemical properties and use in electrochemical sensing including enzyme-based glucose biosensor. Glucose oxidase (GO_x) was immobilized on GQDs modified glassy carbon (GC) and the UV-Vis absorption and fluorescence spectroscopy, electron microscopy, cyclic …

Molecular Sensitivity And Selectivity Of Metal Nanoparticles Decorated Graphene As ‘Smart’ Surface-Enhanced Raman Scattering (Sers) Platforms [Hybrid Poster 1-A], Alexander Banaszak, Tyler Smith

Posters-at-the-Capitol

Raman scattering signal enhancement that uses graphene as support, graphene-enhanced Raman scattering (GERS), is a recent phenomenon. It can produce clean and reproducible Raman signals of chemical molecules with significantly enhanced signal intensity in contrast to traditional surface- (SERS) and tip- enhanced Raman scattering (TERS) techniques. While enhancement in SERS and TERS arise due to the electromagnetic mechanism, GERS also relies on a chemical mechanism and therefore shows unique molecular sensitivity and selectivity. In this work, we developed graphene materials decorated with noble metal (silver and gold) nanoparticles for detection of different chemical molecules e.g. methylene blue (MB) and rhodamine …

Molecules, Surfaces, Crystals: A Quantum Chemical Quest From Fundamentals To Applications, Loredana Valenzano

TechTalks

My research focuses on applying fundamental laws governing the behavior of molecules and materials to predict their real-world performance. Using state-of-the-art quantum chemical approaches as my tool set, I computationally model a wide range of molecular and condensed-matter systems: explosives, pharmaceuticals, porous materials, catalysts, nanomaterials, polymers, soft-matter, films, membranes, surfaces, interfaces, layered materials; hybrid systems: molecules interacting with substrates; and, their properties: structural, energetic, vibrational, electronic, mechanical, adsorption, diffusion. Chemical processes such as reactivity and the change of properties after exposure to external agents (e.g. durability) can also be explored. The results of my investigations can contribute to speeding up, …

Introducing The New 2d-Liquid Chromatograph And High-Resolution Mass Spectrometer In The Chemical Advanced Resolution Methods (Charm) Core Facility At Michigan Tech, Lynn Mazzoleni

TechTalks

A Thermo Scientific Orbitrap Elite Mass Spectrometer (high-resolution Orbitrap Elite MS) and a Dionex UltiMate 3000 two-dimensional liquid chromatographic (2d LC) system were recently acquired. The Orbitrap Elite MS is a hybrid instrument, which includes a dual pressure linear ion trap MS and a compact high-field Orbitrap MS. The instrument design enables high-quality, fast MSn characterization with ultrahigh resolution measurements (R = 240,000 at m/z 400) for mass measurements with less than 1 ppm mass error. Therefore, the instrument has the qualitative capability to identify molecular formulas and structure and, when paired with modern chromatography, provides quantitative assessment of analytes. …

Enriching Health-Related Research Through Glycobiological Approaches, Tarun K. Dam

TechTalks

In the Laboratory of Mechanistic Glycobiology at Michigan Technological University, we have been working in four distinct but related areas. Our findings can significantly influence human health-related research. (1) We have documented a molecular strategy that can improve drug designing. (2) We have shown that the tumor-associated protein galectin-3 can create problems in cancer biomarker assays by hiding the biomarkers. (3) In another project, we reported that the role of galectin-3 in cancer could be more complicated than what is reported in the literature. (4) Our team also detected a novel natural product with anti-fungal and anti-cancer activities.

Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most error-prone step in chemical analysis. A great deal of efforts has been made to develop efficient techniques and protocols for sample preparation to accomplish important goals such as miniaturization and implementation of green analytical methodologies. Solid-phase microextraction (SPME) has successfully eliminated the use of hazardous organic solvents in extraction sampling, sample preparation, preconcentration and sample introduction to the analytical instrument in an effective manner. Ensuring thermal- and solvent-instability of traditional SPME extraction phases represented one of their main drawbacks. This was solved by the introduction of sol-gel SPME phases characterized by enhanced thermal-, solvent-, and …

Aqua­Bis­(2,2'-Bi­Pyridine-[Kappa]2n,N')Chlorido­Nickel(Ii) Chloride Chloro­Form Monosolvate Hemihydrate, Eugenia Vasileiadou, Panagiotis A. Angaridis, Raphael G. Raptis, Logesh Mathivathanan

Department of Chemistry and Biochemistry

The title solvated salt, [NiCl(C₁₀H₈N₂)₂(H₂O)]Cl·CHCl₃·0.5H₂O, contains a mononuclear Ni^II complex cation with 2,2'-bi­pyridine, chloride and aqua ligands forming a slightly distorted ClN₄O octa­hedral coordination set. The charge of the cation is balanced by a chloride anion. In the crystal, half a water mol­ecule and a chloro­form solvent mol­ecule are present per formula unit. Individual components are held together by O-HCl hydrogen bonding and - inter­actions.

Development Of In Vivo Systems For Detecting And Studying Ribosome Inhibition By Small Molecules, Shijie Huang

Chemistry and Chemical Biology ETDs

The ribosome is the quintessential antibacterial drug target, with many structurally and mechanistically distinct classes of antibacterial agents acting by inhibiting ribosome function. Detecting and quantifying ribosome inhibition by small molecules and investigating their binding modes and mechanisms of action are critical to antibacterial drug discovery and development efforts. To develop a ribosome inhibition assay that is operationally simple, yet provides direct information on the drug target and the mechanism of action, we have developed engineered E. coli strains harboring an orthogonal ribosome controlled green fluorescent protein reporter that produce fluorescent signal when the O-ribosome is inhibited. As a proof …

Development And Application Of An Expanded Streptomyces Genetic Code, Jingxuan He

Chemistry and Chemical Biology ETDs

Actinobacteria, especially those of genus Streptomyces, are a prominent source of bioactive natural products. The ability to site-specifically incorporate unnatural amino acids (UAAs) into natural product biosynthetic enzymes and ribosomally derived peptides in these organisms would constitute a valuable tool for drug discovery and development. The work described in this dissertation focuses on development and application of an expanded Streptomyces genetic code, including development of UAA incorporation systems based on amber suppression and sense codon reassignment, structural diversification of the model thiopeptide natural product thiostrepton using UAAs, and mapping protein-protein interactions in type II polyketide biosynthetic enzymes using photocrosslinking …

Engineering Small Molecule Based Dimerization To Induce Translation And Provide Optogenetic Control, Catherine Wright

Chemistry and Chemical Biology ETDs

We wanted to develop a system that combines the spatial control of photoactivation and control of translation to build a tool to spatially control translation in neurons. This kind of tool could be used to investigate the role of spatially controlled translation of any protein in neural behavior. In this way the development and growth of neural processes could be studied to elucidate the mechanisms for spatially sensitive events such as pathfinding, repair, or long-term potentiation.

Chemically induced dimerization was used to install a switch into the activation of translation for specific genes. An abscisic acid (ABA) dependent dimerization of …

Going Beyond The Analysis Of Common Contaminants: Target, Suspect, And Non-Target Analysis Of Complex Environmental Matrices By High-Resolution Mass Spectrometry, Anna Katarina Huba

FIU Electronic Theses and Dissertations

The advancements in the field of analytical chemistry, and especially mass spectrometry, have been redefining the field of contaminant detection. While more traditional analysis was sufficient to screen for a small number of well-known compounds, new techniques such as high-resolution mass spectrometry, have enabled a fairly comprehensive screening for previously unknown contaminants. This is enormously beneficial with respect to the analysis of water, air, or soil quality in a society that continuously introduces novel anthropogenic compounds into the environment. This dissertation, thus, focused on the analysis of the uncharacterized portion of compounds in two types of complex environmental matrices (i.e., …

Peridynamic Modeling Of Ruptures In Biomembranes, Michael Taylor, Irep Gözen, Samir Patel, Aldo Jesorka, Katia Bertoldi

Michael Taylor

We simulate the formation of spontaneous ruptures in supported phospholipid double bilayer membranes, using peridynamic modeling. Experiments performed on spreading double bilayers typically show two distinct kinds of ruptures, floral and fractal, which form spontaneously in the distal (upper) bilayer at late stages of double bilayer formation on high energy substrates. It is, however, currently unresolved which factors govern the occurrence of either rupture type. Variations in the distance between the two bilayers, and the occurrence of interconnections (“pinning sites”) are suspected of contributing to the process. Our new simulations indicate that the pinned regions which form, presumably due to …

Physical Properties Of Traditional And Water-Miscible Oil Paints As Assessed By Single-Sided Nmr, Nicholas Anthony Sanchez Udell

Dissertations, Theses, and Masters Projects

Single-sided NMR has been demonstrated as a useful technique for the inexpensive and non-invasive study of cultural heritage objects, including numerous different painting and paint samples. The relatively recent invention of water-miscible oil paints – a new form of environmentally friendly oil paint that can be thinned and cleaned by water – provides a need for analysis of the physical properties of the cured paint films. Single-sided NMR offers an excellent analytical tool to study the structural effects of the emulsifying agent present in water-miscible oil paints on the paint linoxyn network by measuring the transverse (T2) relaxation times for …

Evaporation Induced Self-Assembly And Characterization Of Nanoparticulate Films: A New Route To Bulk Heterojunctions, Yipeng Yang

Doctoral Dissertations

Polymer-based semiconducting materials are promising candidates for large-scale, low-cost photovoltaic devices. To date, the efficiency of these devices has been low in part because of the challenge of optimizing molecular packing while also obtaining a bicontinuous structure with a characteristic length comparable to the exciton diffusion length of 10 to 20 nm. In this dissertation we developed an innovative evaporation-induced nanoparticle self-assembly technique, which could be an effective approach to fabricate uniform, densely packed, smooth thin films with cm-scale area from home-made P3HT nanoparticles. Unlike the previous reports of nanoparticle-based film formation, we use a mixture of two solvents so …

Aggregation And Coagulation Of C60 Fullerene As Affected By Natural Organic Matter And Ionic Strength, Hamid Mashayekhi

Doctoral Dissertations

With widespread production and use of C₆₀ fullerene nanoparticles, their release to the environment and natural waters is inevitable. The colloidal nature of C₆₀ fullerene in the aquatic environment significantly influences its behavior in the environment including its transport, bioavailability and toxicity to different organisms. Natural organic matter (NOM) is a ubiquitous and reactive material in aquatic environments with significant structural heterogeneity. Therefore, the effect of NOM molecules on the colloidal behavior of fullerene particles needs to be studied. A major part of NOM consists of humic acids (HA). HAs have pronounced effects on the aggregation of C …

Cell Modulation Using Functionalized Nanoparticles, Rui Tang

Doctoral Dissertations

Monolayer functionalized ultra-small gold nanoparticles (AuNPs) provide a versatile platform for applications in cell research. Through rational design of surface ligands, the chemistry of AuNPs are precisely regulated at atomic level. In this dissertation, applications of AuNPs in cell modulation are discussed. The topics are split into two categories. In the first category, functionalized AuNPs are harnessed to generate a robust monolayer on cell culture surface for cell modulation. The proliferation and behavior of different types of cancer cells and normal cells are modulated by tuning the surface ligands of AuNPs. Fate decision of mesenchymal stem cells are also modulated …

Functional Hydrophilic Polymers For Solution Assembly And Non-Viral Gene Therapy, Rachel A. Letteri

Doctoral Dissertations

This thesis examines functional hydrophilic polymers designed in linear and comb architectures and that carry functional moieties in the context of solution assembly and non-viral gene therapy. Specifically, polymers containing cations, zwitterions, and reactive groups are investigated as non-viral gene therapy reagents and at oil-water interfaces on droplets. Cations facilitate complexation of nucleic acids and interaction with cellular and nuclear membranes, while zwitterions impart stimuli-responsive solution properties and biocompatibility. Reactive groups, including alkenes, alkynes, and benzylic methylenes, permit post-polymerization modification leading to tunable polymer properties in solution and at interfaces. This work expands the knowledge base related to solution, interfacial, …