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Full-Text Articles in Analytical Chemistry
Sers For The Detection Of Trace Materials, Omari Kirkland
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 …
Nanoscale Imaging Of Electrocatalytic Nanomaterials By High-Resolution Scanning Electrochemical Microscopy, Xiang Wang
Nanoscale Imaging Of Electrocatalytic Nanomaterials By High-Resolution Scanning Electrochemical Microscopy, Xiang Wang
Dissertations, Theses, and Capstone Projects
Numerous insights of the structure–electrochemical activity relationship of nanocatalysts have been obtained by using macroscopic electrochemical measurements over the last several decades. However, signals measured by large electrodes are inevitably averaged out of many nanocatalysts, non-uniformed sizes, uneven morphologies, and multiple crystallographic facets. Over the last ten years, Scanning Electrochemical Microscopy (SECM) has advanced electrochemical measurements toward micro- to nanoscale level at a high spatial resolution. The advantages of using nanoelectrode in SECM include fast mass transfer of reactive species, dominated radial diffusion pattern, small double layer capacitance and small RC constant. In this thesis, high-resolution SECM is applied to …
Sensitized Photooxidation Of Prenylated Compounds: Mechanisms Of Downstream Dark Effects And Phototoxicity Priming, Shakeela Jabeen
Sensitized Photooxidation Of Prenylated Compounds: Mechanisms Of Downstream Dark Effects And Phototoxicity Priming, Shakeela Jabeen
Dissertations, Theses, and Capstone Projects
This thesis consists of four chapters as detailed below.
Chapter 1 discusses a singlet oxygen priming mechanism. Airborne singlet oxygen derived from photosensitization of triplet dioxygen is shown to react with an alkene surfactant (8-methylnon-7-ene-1 sulfonate) leading to ‘ene’ hydroperoxides that in the dark inactivate planktonic E. coli. The ‘ene’ hydroperoxide photoproducts are not toxic on their own, but they become toxic after the bacteria are pretreated with singlet oxygen. The total quenching rate constant (kT) of singlet oxygen of the alkene surfactant was measured to be 1.1 × 106 M−1 s− …
Photosensitization And Analytical Study On Reactive Oxygen Intermediates: Self-Sorting Surface Radicals And “On-Off” Sensitizer Function Mechanisms, Sarah J. Belh
Dissertations, Theses, and Capstone Projects
This thesis consists of four chapters which are detailed below. Chapter 1 is an introductory chapter, which lays out the background and purpose of the research.
Chapter 2 describes a study of the mobility of alkoxy radicals on a surface by detection of their recombination product. A novel method called symmetrical product recombination (SRP) utilizes an unsymmetrical peroxide that upon sensitized homolysis recombines to a symmetrical product [R'OOR → R'O•↑ + •OR → ROOR]. This allows for self-sorting of the radical to enhance the recombination path to a symmetrical product, which has been used to deduce surface migratory aptitude. SPR …
Study Of Reaction Dynamics Of Protonated/Deprotonated And Radical Cations Of Guanine In Nucleobases And Nucleosides: Singlet Oxygen Oxidation, C8-Water Addition, Cross-Linking With Lysine And Base-Pair Dissociation, Yan Sun
Dissertations, Theses, and Capstone Projects
Among the four DNA nucleobases, guanine (G) has the lowest oxidation potential and represents a preferential target for oxidation and ionization. This leads to the formation of guanine radical cation (G•+) in various oxidative environments. Of the biologically relevant oxidants, electronically excited singlet oxygen (1O2) exclusively damages the guanine bases and gives rise to mutagenesis, DNA-protein cross-linking and cellular death. Combining our home-made electrospray ionization (ESI) guided-ion-beam tandem mass spectrometer, with reaction potential surface calculations and kinetics modeling, five projects have been accomplished as described below.
In project 1, the reactions of deuterated water …