Thèse de doctorat : Chimie et chimie physique : Ecully, Ecole centrale de Lyon : 2008. / Titre provenant de l'écran-titre. 173 références.

Thèse doctorat : Chimie et chimie physique : Ecully, Ecole centrale de Lyon : 2008. / 173 références.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 307-315). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 205-212). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 78-89).

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 156-160).

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xv, 146 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 117-129).

This thesis presents spectroscopic studies of metallic nanoparticle localized surface plasmons and plasmon enhanced fluorescence. We investigated the dielectric sensitivity of silver nanoprisms to an external electric field and gold nanorods to the formation of a self-assembled surface monolayer. Dark field microscopy was used to image plasmonic scattering from single nanoparticles, and a liquid crystal tunable filter was used to construct corresponding spectra. The plasmon resonances of silver nanoprisms displayed both reversible red shifts and irreversible blue shifts along with drastic intensity changes upon exposure to an applied bias. The plasmon resonances of gold nanorods showed sensitivity to the presence of alkanethiol molecules adhered to the particle surface by a moderate red shift. An increase in the effective external dielectric caused a shift toward longer wavelengths. We imaged plasmon enhanced fluorescence in order to optimize experimental parameters for a developing project that can characterize nanoparticle structure on sub-wavelength dimensions. Preliminary controls were performed to account for the effect of O₂ plasma treatment, solvent and alkanethiol monolayer formation on surface plasmon resonances. We found that O₂ plasma treatment for different time intervals did not result in a plasmon shift compared to untreated nanoparticles exposed to N₂; however when exposed to solvent the surface plasmons of the treated particles shifted five times as far toward the red. Interestingly, the solvent effect only resulted in a plasmon shift when the particles were N₂ dried after solvent incubation. Gold nanorods incubated in ethanol showed no wavelength maximum shift in pure solvent over time, but shifted moderately to the red after incubation in a solution of alkanethiol molecules. Conditions for the plasmon enhanced fluorescence study were optimized using a dye conjugate of the same alkanethiol molecule used previously by formation from solution in a monolayer on the gold nanorod surface. The appropriate synthesis for dye functionalization, molecular concentrations, solvents and optical settings were determined. / text

This research focuses on developing selective FRET peptidyl metal ion sensors as a portable and less costly alterative to traditional atomic spectrometric techniques. Initially, a selective sensor for Cu²⁺ was developed that consisted of glycine and aspartic acid residues and the FRET pair tryptophan (donor) and dansyl (acceptor). Aspartic acid's affinity for hard acid metals and Cu²⁺'s preference for square planar coordination was used as the basis of design. Although the sensor was designed to utilize the signal enhancement capabilities of FRET, quenching of both fluorophores occurred and proved to be the most sensitive means of quantifying Cu²⁺ binding. Nonetheless, the sensor provided a selective and sensitive response to Cu²⁺ at pH 7.0. Another FRET peptide metal ion sensor was designed with the help of a biological starting point, the mercury binding protein MerP. A sensitive FRET enhancement or "turn on" response was observed for Hg²⁺, as well as Zn²⁺, Cd²⁺ and Ag²⁺ in pH 7.0 solution. While a selective response for only Hg²⁺ was the ultimate goal of this study, this sensor is still an improvement over current systems which utilize a quenching mechanism for Hg²⁺ detection. While the previous studies investigated these sensors in aqueous solutions, the end goal was to devise a sensor based on an immobilized peptide chelator with FRET capabilities. To this end, immobilized, fluorophore labeled peptide studies were then conducted on Tentagel resin using a visible region FRET pair. A flow injection fluorescence analysis system using the immobilized fluorophore labeled peptide as the ion exchange material was also designed, allowing for the efficient analysis of fluorescence solutions. In addition to the work conducted with FRET sensors, studies were also conducted using magnetic [gamma]-Fe₂O₃ nanoparticles with PLCys immobilized onto the surface. The [gamma]-Fe₂O₃ nanoparticles are ideal supports since they can be magnetically collected and have a very large surface area to mass ratio. Finally, a method was developed to quantitatively screen metals bound to single Tentagel beads with immobilized peptides using ETV-ICP-MS. This method is an improvement over existing methods because it is nondestructive and simultaneously provides the absolute content of all metals bound.