Chemistry Weekly Seminar - Osai Clarke, PhD Candidate
Osai Clarke, PhD candidate in the Department of Chemistry, University of Saskatchewan will present a seminar at 1:30 p.m. via Zoom.
Title
Anisotropic Gold Nanoparticles for Surface Enhance Spectroscopies
Abstract
Dagger shaped gold nanoparticles electrodeposited on conductive indium tin oxide (ITO) films exhibit optical extinction from the near-IR to mid-IR frequencies. The gold nano-daggers (AuNDs) are assessed as potential enhancing interfaces for dual-modality, spectroelectrochemical, surface-sensitive vibrational spectroscopy; specifically, surface-enhanced Raman spectroscopy (SERS) using 1064 nm excitation and attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) using a broadband emission source. The potential dependent spectra of pyridine establishes the SERS suitability of the AuND@ITO interfaces and confirms the N-bonded adsorption model. The ability of the substrates to provide surface enhancement for both SERS and ATR-SEIRAS allows an analogous study of 4-methoxypyridine (MOP) and, with the assistance of DFT calculations and surface selection rules, demonstrates that MOP adsorbs with a vertical orientation over a broad range of applied potentials. In a proof of principle experiment, the SEIRAS and SERS spectra of the same self-assembled monolayer of 4-mercaptobenzoic acid (MBA) is reported using a AuND@ITO film supported on a ZnSe hemisphere.
Date: Friday, February 5, 2021
Time: 1:30 p.m.
Via Zoom video conference (link available by request to chem.dept@usask.ca)