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Influence Of Shelling Temperature And Time On The Optical And Structural Properties Of Cuins2/Zns Quantum Dots, Colette Robinson

Graduate Theses and Dissertations

CIS/ZnS core/shell QDs are an important class of nanomaterials for optoelectronic, photovoltaic and photoluminescence applications. They consist of lower toxicity materials than the prototypical II-VI Cd-based QDs and show long fluorescence lifetimes, which generates prospective in biological imaging applications. It is vital to develop reproducible synthetic methods for this new class of nanomaterials in order to maintain small sizes with high QYs. CIS core QDs have been shelled with ZnS at various temperatures from 90-210°C for reaction times ranging from 20-140 minutes to examine the role of thermodynamics and kinetics on the shell growth. Using HR-TEM and ICP-MS, it was …

Fabrication, Characterization, And Application Of Carbon Nanoparticles For The Detection Of Heavy Metal Ions In Aqueous Media, Aaron Michael Simpson

MSU Graduate Theses

This research set out to develop a method for producing Carbon nanoparticles (CNPs) from glycerol and use them to detect Cu2+, Hg2+, and Pb2+ ions in aqueous solution. Three synthesis methods were developed using the following mixtures: (1) glycerol and silica, (2) glycerol, silica, and H3PO4, and (3) glycerol with H3PO4. The structure of the particles was characterized using a variety of spectroscopic techniques. Size distributions were obtained from scanning electron microscopy images. The particles were spherical with average diameters of 66, 58, and 89 nm respectively and believed to consist of a carbon core with carboxylic acid and alcohol …

Photochemical Tools For Fluorescent Labeling Of Endogenous Proteins, Stephen T. Mccarron

Doctoral Dissertations

The study of the dynamic movements of membrane bound proteins is typically achieved through an exogenously applied fluorescent tag or genetic modification of a receptor of interest to spatiotemporally monitor protein location. Techniques often used for labeling proteins include overexpression of a fluorescent protein such as GFP fused to a target protein or the application of antibodies. These methods benefit from superb specificity towards a receptor of interest, but may impose unforeseen consequences when studying natural protein movements. Thus, it is advantageous to development small, modular probes that would allow for visualization of endogenous membrane bound receptors in a minimally …

Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby

Chemistry & Biochemistry Theses & Dissertations

Organic aerosols (OA) are universally regarded as an important component of the atmosphere based on quantitative significance as well as the far-reaching impact they have on global climate forcing and human health. Despite the acknowledged importance, OA amounts and impacts remain the largest uncertainties regarding radiative forcing estimates. Incomplete chemical characterization of aerosol organic matter (OM) and a lack of concrete source apportionment is a major source of this uncertainty. The primary focus of this study is to provide much needed molecular details regarding ambient OA from key emission sources, and establish links between molecular and optical properties.

Complete chemical …

Structural And Functional Analysis Of The Reaction Center Complexes From The Photosynthetic Green Sulfur Bacteria, Guannan He

Arts & Sciences Electronic Theses and Dissertations

The reaction center (RC) complex of the green sulfur bacterium Chlorobaculum tepidum is composed of the Fenna-Matthews-Olson (FMO) antenna protein and the reaction center core (RCC) complex. The RCC complex has four subunits: PscA, PscB, PscC, and PscD. The structure of the intact and functional FMO-RCC complex was studied by chemically cross-linking the purified sample followed by biochemical and spectroscopic analysis. The interaction sites of the cross-linked complex were also studied using LC-MS/MS. A structural model is proposed based on those results. In addition, the RCC complexes were purified, both the PscA-PscC complex from the Chlorobaculum tepidum and the PscA-PscB …

Synthesis And Functionalization Of Fluorescent Quantum Dot Bioconjugates For Cellular Imaging Of Directed Gene Therapy, Jason Matthew Davis

MSU Graduate Theses

Herein, I optimize a method for synthesis and bioconjugation of water-soluble, fluorescent CdSe/ZnS quantum dots (QDs) for targeted cellular delivery of DNA. Core CdSe QDs were synthesized in high temperature organic solvents and passivated with a ZnS shell to increase quantum yield. The fluorescent QD nanoparticles were made water-soluble by enveloping them with an amphiphilic polymer. These aqueous nanoparticles were functionalized with tertiary amines to impart a positive charge, allowing electrostatic binding to negatively-charged DNA. The conjugated QDs were characterized using zeta potential and electrophoresis to gauge their ability to electrostatically bind DNA. The QDs were further modified by conjugation …

Design And Development Of Bodipy-Based Fluorescent Probes For Sensing And Imaging Of Cyanide, Zn (Ii) Ions, Lysosomal Ph And Cancer Cells, Jingtuo Zhang

Dissertations, Master's Theses and Master's Reports - Open

BODIPY (4,4-Difluoro-3a,4a-diaza-s-indacene) dyes have gained lots of attention in application of fluorescence sensing and imaging in recent years because they possess many distinctive and desirable properties such as high extinction coefficient, narrow absorption and emission bands, high quantum yield and low photobleaching effect. However, most of BODIPY-based fluorescent probes have very poor solubilities in aqueous solution, emit less than 650 nm fluorescence that can cause cell and tissue photodamages compared with bio-desirable near infrared (650-900 nm) light. These undesirable properties extremely limit the applications of BODIPY-based fluorescent probes in sensing and imaging applications. In order to overcome these drawbacks, we …