The influence of surfactants on the electron-transfer reaction at self-assembled thiol monolayers modifying a gold electrode

Monolayer films of thiols with different terminal groups (-CH3, -COOH and - NH2) were prepared on gold electrodes using a self-assembling procedure. Cy clic voltammetry was used to investigate the electron-transfer reaction of potassium ferricyanide at the thiol modified gold electrode in the presence of surfactants. It was found that surfactants show some effects on the ele ctron-transfer reaction at the thiol modified electrode. Cationic surfactan ts can improve the reversibility of a redox reaction at the thiol modified gold electrodes, while anionic surfactants cause a little inhibition of ele ctron transfer of the redox at both methyl and carboxyl terminal thiol modi fied gold electrodes. Surfactants can interact with thiol monolayers in dif ferent ways, changing the structure and properties of the monolayer film, a nd can further affect electron transfer at the modified gold electrode. (C) 2000 Elsevier Science S.A. All rights reserved.