University of Western Ontario - Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Chemistry

Supervisor

Dr. François Lagugné-Labarthet & Dr. Peter R. Norton

Delay of Publication

1

Abstract

One of the main challenges in analytical science and technology is to develop devices that provide unambiguously the chemical nature of the material of interest with the minimum intrusiveness, the smallest amount of analyte, and the shortest acquisition time. Among the promising methods for such purpose, optical spectroscopy such as surface-enhanced Raman scattering is considered a suitable option. This spectroscopic technique takes advantage of the interaction between an optical field and metallic nanostructures to magnify the electromagnetic field in the vicinity of the nanostructure, resulting in an amplified signal of the vibrational fingerprints of the adsorbed molecules onto the metallic surface.

In this Thesis, the rational design and fabrication of gold nanostructures optimized to probe molecular systems, at the monolayer level in a variety of configurations, is described. Using advanced nanofabrication techniques, two-dimensional arrays of metallic nanostructures were inscribed onto glass slides. The fabricated SERS platforms were first physically and optically characterized. Then, a rational analysis of the properties was performed through numerical calculations and experimental measurements, to estimate the polarization dependence of such nanostructures. The results led toward the optimization of the SERS platforms, and to the study of different complex surface molecular systems. Finally, these platforms were embedded in a microfluidic device for in-situ probing of molecules opening the possibility to develop micro total analysis in combination with Raman measurements.