Amperometric Biosensor for Hydrogen Peroxide Based on Glucose Oxidase Immobilized in Au Nanoparticles and 2,3-Dimercaptosuccinic Acid Self-Assembly Monolayers

摘要

A simple amperometric biosensor for the analytical detection of hydrogen peroxide was developed. The biosensor was prepared by the immobilization of glucose oxidase (GOD) in the nanostructure matrix constructed through electrochemical deposition of Au nanoparticles (AuNPs) upon 2, 3-dimercaptosuccinic acid (DMSA) SAMs formed on Au electrode. The fabricated biosensor had a fast response of H_2O_2 (<10 s), and an excellent linear range of concentration from 2×10~(-6) to 3.5×10~(-3) M with a low detection limit of 0.65 μM (S/N = 3) under the optimum conditions. The Michaelis-Menten constant of the immobilized GOD was 2.0 mM, displaying a high affinity of the GOD toward H_2O_2 without loss of enzymatic activity in nano-substrate.