Characterization of n-alkanethiolate monolayers adsorbed to electrochemically deposited gold nanocrystals on glassy carbon electrodes

Abstract

In this work we combine electrochemical metal deposition with the self-assembly of thiolate monolayers in an effort to develop a novel method for attaching predefined functional groups to glassy carbon (GC) electrodes. Gold nanocrystals were electrochemically deposited on polished GC substrates by a potential step and subsequently modified by exposure to ethanolic solutions of n-alkanethiols. The structure of the resultant monolayers was then studied using electrochemical blocking analysis and infrared reflection absorption spectroscopy. Our analyses indicate that monolayers adsorbed to gold nanocrystals on GC adopt a more disordered structure relative to similar monolayers adsorbed to planar Au substrates. This is likely due to a high density of step sites on electrochemically deposited Au particles. Finally, we demonstrate our ability to employ a sequence of deposition and modification steps to introduce multiple functional groups on a single GC electrode.