Study on the influence of anionic and cationic surfactant on Au-colloid modified electrode function by cyclic voltammetry and electrochemical impedance techniques

The influence of different surfactants on Au-colloid modified electrode function has been investigated by using cyclic voltammetry and electrochemical impedance techniques. Colloidal Au was self-assembled onto the gold electrode through the thiol-groups of 1,6-hexanedithiol (HDT) monolayer. It was found that some HDT molecules stood on the gold electrode and some molecules lay on the electrode by using the quartz crystal microbalance (QCM). A cathodic peak at about 0.486 V (vs. SCE) was observed at the bare gold electrode and the Au-colloid modified electrode. Cyclic voltammetry was used to investigate the influence of different surfactants on the cathodic peak of Au-colloid modified electrode. Electrochemical impedance technique was also used to study the electron transfer ability of the redox probe on Au-colloid modified electrode after being immersed in different surfactants. The results showed that anionic surfactant and cationic surfactant exhibit different behaviors, the reason of which was discussed.