Electrochemical characteristics of H2O2 microarray electrodes as base elements of biosensors

The electrochemical characteristics were examined of band- and square-type MAEs (microarray electrodes) with 10, 20 and 30 μm band width and side length prepared by using standard planar processing in K3Fe(CN)6 solution. Among them, S1–5 square-type MAE with 10 μm side length and 9.0×10−3 mm2 in the total area exhibits the largest current density and the shortest response time. The H2O2 calibration curve obtained at the S1–5 shows linearity from 0.1 to 5.0 mmol/l, a mean slope of 550 nA/mmol/l with a CV (variation coefficient) of 16.1%. A glucose sensor based on the S1–5 was prepared and its sensitivity was 21 nA/mmol/l, ten-fold greater than that of a single ME (microelectrode) reported lately.