ANALYTICAL APPLICATION OF SELF-ASSEMBLED MONOLAYERS ON GOLD ELECTRODES - CRITICAL IMPORTANCE OF SURFACE PRETREATMENT

Polycrystalline bare gold electrodes have been used as substrate for t he preparation of self assembled monolayers (SAMs) of alkanethiols. Ch emical cleaning and several mechanical polishing procedures of the ele ctrode have been carefully tested in order to prepare monolayers of oc tadecyl-, mercaptans. By analyzing the cyclic voltammetric curves of h exacyanoferrate III and chlorpromazine and the electrochemical desorpt ion of the coated monolayer, it appeared that the response at the bare electrodes is related to the cleaning procedure and that the structur e of SAM coated gold electrodes is influenced by the polishing materia l used, i.e. diamond or alumina slurry. Electrochemical results have b een confirmed by Auger analysis of the electrode surface.