Adsorption and Desorption of Au Nanoparticles Monitored by Infrared Spectroscopy

Abstract

We show that infrared absorption spectroscopy can probe the adsorption and desorption process of Au nanoparticles onto silica surface from colloidal suspension. When the Au nanoparticles come into the evanescent field of the infrared (IR) beam in attenuated total reflection (ATR) geometry, IR vibrational signal is detected due to the surface enhanced IR absorption. Quantitative analysis of the adsorption kinetics is possible by monitoring the time dependence of the IR signals.