Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Zhang, Dongmao
Committee Member
Wipf, David O.
Committee Member
Mlsna, Todd E.
Committee Member
Fitzkee, Nicholas C.
Committee Member
Foster, Stephen C.
Date of Degree
12-9-2016
Document Type
Dissertation - Open Access
Major
Chemistry
Degree Name
Doctor of Philosophy
College
College of Arts and Sciences
Department
Department of Chemistry
Abstract
The use of spectrofluorometers to examine nanomaterials is quite popular using either fluorescence or synchronous measurements. However, understanding how a material’s optical properties can influence spectral acquisition are of great importance to accurately characterize nanomaterials. This dissertation presents a series of computational and experimental studies aimed at enhancing the quantitative understanding of nanoparticle interactions with matter and photons. This allows for more reliable spectrofluorometer based acquisition of nanoparticle containing solutions. Chapter I presents a background overview of the works described in this dissertation. Correction of the gold nanoparticle (AuNP) inner filter effect (IFE) on fluorophore fluorescence using PEGylated AuNPs as an external reference method is demonstrated in Chapter II. The AuNP IFE is corrected to quantify tryptophan fluorescence for surface adsorbed proteins. We demonstrate that protein adsorption onto AuNPs will only induce ~ 20% tryptophan fluorescence reduction instead of the commonly assumed 100% reduction. Using water Raman intensities to determine the effective path lengths of a spectrofluorometer for correction of fluorophore fluorescence is discussed in Chapter III. Using Ni(NO3)2 and K2Cr2O7 as Raman IFE references, the excitation and emission path lengths are found to exhibit chromophore and fluorophore independence, however path lengths are spectrofluorometer dependent. Finally, ratiometric resonance synchronous spectroscopy (R2S2) is discussed in Chapter IV. Using a combination of UV-vis and R2S2 spectroscopy, the optical cross sections of a wide range of nanomaterials were determined. Also on-resonance fluorescence in solution is demonstrated for the first time. The nanoparticles discussed range from photon absorbers, scatterers, simultaneous photon absorbers and scatterers, all the way to simultaneous photon absorbers, scatterers, and emitters.
URI
https://hdl.handle.net/11668/19501
Recommended Citation
Nettles, Charles Bruce, "Material Characterization using Spectrofluorometers" (2016). Theses and Dissertations. 3017.
https://scholarsjunction.msstate.edu/td/3017
Comments
nanoparticles||ratiometric resonance synchronous spectra||resonance light scattering||fluorescence||inner filter effect