Degree

Doctor of Philosophy (PhD)

Department

Chemistry

Document Type

Dissertation

Abstract

Recent exploration in the field of nanomaterials has led to the investigation of noble metal nanoparticles for various nanomedical applications. The spectroscopy of these nanoparticles is studied using both linear and nonlinear optical processes such as second harmonic generation (SHG), two-photon fluorescence (TPF), and extinction spectroscopy. Details pertaining to the growth dynamics of silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) and gold-silver-gold core-shell-shell (Au@Ag@Au CSS) nanoparticles (NPs) are currently being investigated in order to obtain better control and optimization of the nanoparticle size and surface morphology. Transmission electron microscopy (TEM) images show that the nanoparticles have tunable core and shell sizes and are spherically shaped. Hybrid plasmonic nanoparticles consisting of gold and silver feature adjustable plasmonic spectra and enhanced photothermal properties. Temperature studies in the form of photothermal measurements utilizing 800 nm laser irradiation display an increase in observed photothermal effect when studying colloidal Au@Ag@Au CSS NPs in relation to spherical silver and gold nanoparticles. Preliminary transient absorption studies have also been performed in order to study the excited state dynamics of these hybrid plasmonic nanoparticles. The synthesis and characterization of various CS and CSS NPs with the use of second harmonic generation (SHG) spectroscopy allows for the detailed examination of optical and chemical interactions of CS and CSS NPs. This approach provides the ability to further investigate the growth dynamics of hybrid plasmonic NPs and learn more about the surface characteristics of the newly synthesized nanoparticles in real time.

Date

1-7-2025

Committee Chair

Haber, Louis H.

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