Array of Single Nanocavity Electrodes for Lab-on-a-Chip

Abstract

Electrochemical methods have been frequently employed in lab-on-a-chip systems for biosensing and biomedical analysis of analytes. For this goal, fabrication of electrode is one of important steps because material and structure of electrode have significant effects on performance of electrochemical detection. In these days, various nano-sized electrodes were prepared by several methods because they have some advantages compared to macro/micro-sized electrodes such as enhanced mass transport, improved signal to noise ratio, and minimal iR drop. In this study, to get higher current and to keep the advantages of nano-sized electrode, the array of a nanocavity electrode with controlled diameter and structure was fabricated by photolithography and focused ion beam. Each electrode in the array is designed to work individually, which indicates that simultaneous and multiplex detection of several biomarkers is enabled for efficient lab-on-a-chip system. First of all, it is necessary to investigate the electrochemical behavior of single nanocavity electrodes. The redox behavior was intensively studied according to scan rates, kinds of redox species, concentrations of redox species, kinds of supporting electrolyte, and concentrations of supporting electrolytes.