Spectroelectrochemical analysis of self-assembled monolayers on gold

Abstract

Organic thin films prepared from long-chain organothiols have been self-assembled on gold surfaces and their chemistry and structural properties studied by physical, electrochemical and spectroscopic methods. The mechanism of charge transfer across these organic thin films was of particular interest and was studied by combined spectroscopic and electrochelllical methods. The influences of chain length, terminal functional group I and sol vent on the electrochemical kinetics were studied. Evidence of a kinetic barrier to charge transfer pointed to a charge-diffusion mechanism across the organic thin films. An Infrared Reflection-Absorption Spectroscopy (IRRAS) method was developed to monitor the titration of acid functionalized films. The method compared favorably with the currently-used goniometry method because the IRRAS method was faster, less prone to operator bias, and provided structural information.