Analytical Sciences

Abstract − Analytical Sciences, 33(7), 839 (2017).

Direct Electron Transfer-type Bioelectrocatalysis of Peroxidase at Mesoporous Carbon Electrodes and Its Application for Glucose Determination Based on Bienzyme System
Hong-qi XIA, Yuki KITAZUMI, Osamu SHIRAI, and Kenji KANO
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
Non-catalytic direct electron transfer (DET) signal of Compound I of horseradish peroxidase (POD) was first detected at 0.7 V on POD/carbon nanotube mixture-modified electrodes. Excellent performance of DET-type bioelectrocatalysis was achieved with POD immobilized with glutaraldehyde on Ketjen Black (KB)-modified electrodes for H2O2 reduction with an onset potential of 0.65 V (vs. Ag | AgCl | sat. KCl) without any electrode surface modification. The POD-immobilized KB electrode was found to be suitable for detecting H2O2 with a low detection limit (0.1 μM at S/N = 3) at –0.1 V. By co-immobilizing glucose oxidase (GOD) and POD on the KB-modified electrode, a bienzyme electrode was constructed to couple the oxidase reaction of GOD with the DET-type bioelectrocatalytic reduction of H2O2 by POD. The amperometric detection of glucose was performed with a high sensitivity (0.33 ± 0.01 μA cm−2 μM−1) and a low detection limit (2 μM at S/N = 3).