Reversible Potential Change of Ferrocenylthiol Monolayers Induced by Atomic Force Microscopy

Abstract

Self-assembled monolayers (SAMs) of alkanethiol with a ferrocenyl group (ferrocenylthiol) are well known as electrochemically active ultrathin films. In this study, ferrocenylthiol SAMs were locally modified by applying DC bias voltages to the SAMs using atomic force microscopy (AFM) and the surface potential distributions of the modified areas were investigated by Kelvin probe force microscopy. A positive surface potential shift was detected in the negatively biased regions. In addition, a reversible surface potential change was successfully detected. The surface potential changes were discussed in terms of the electrochemical activity of the ferrocenyl groups.