Voltammetry at gap electrode using redox cycling and its application

Abstract

As electrochemical fabrication, the research using fast mass transport have been emerging. In this thesis, we study easy and fast fabrication of micro-gap electrode and, its application using redox cycling. We first devise gap electrode employing uniform-sized spherical beads as spacers to control gap thickness ranging from 500 nanometer to 8 micrometer. After that, we confirmed the gap by using SEM (Scanning electron microscope) and cyclic voltammetry, and measured the resulting current. The gap is applied to the biosensor capable of detecting dopamine in the presence of ascorbic acid. Additionally, the molecule diode modifying one of Au electrodes with ferrocene terminated self-assembled monolayer is developed to offer unidirectional charge transfers. As a result, High rectification ratio (ca. 170) as well as fast response time (7.5 ms) is obtained at 4 micrometer gap and we confirmed that both rectification ratio and response time are programmable depending on gap thickness.