Development of High-Sensitive Detection System for Redox Analytes Having a Standard Potential Higher Than O2 Evolution by Using Micropatterned Conductive Boron-Doped DLC Electrodes

High sensitive electroanalytical system for redox analytes with standard potential higher than O2 evolution was developed by realizing interdigitated microarray electrodes based on boron-doped DLC (B-DLC-IDA). For Ce3+/4+ with the standard potential of 1.6 V, the amplification of response current derived from redox cycling was observed at B-DLC-IDA in the dual mode measurement. The amperometric current was amplified 180-fold by applying the potential of 1.7 V and 0.8 V to the collector and the generator electrodes in chronoamperometriy (CA) at the dual mode measurement. Theoretical detection limit (S/N = 3) toward Ce3+ was 0.13 μM. This detection limit was able to be improved to the value 2 orders of magnitude lower than that at B-DLC flat electrode by developing the electroanalytical system using B-DLC-IDA electrodes.