A Simple Hydrogen Peroxide Biosensor Based on Catalase Immobilized in Nano-Structural Composite Film

Abstract

A robust and effective nanocomposite film modified gold electrode based on 2, 3-dimercaptosuccinic acid ( DMSA ) and Au nanoparticles ( AuNPs ) was prepared by a method combining self-assembly with underpotential deposition. Direct electron transfer can easily take place between a gold electrode and catalase molecules anchored on AuNPs films. Besides, the CAT/AuNPs/DMSA multilayer film had a relatively rapid and satisfactory response toward H 2 O 2 with a wide linear range from 3.0×10 6 to 5.86×10 3 M and a low detection limit of 3.0 μM (S/N = 3). The Michaelis-Menten constant of the immobilized CAT was calculated to be 2.2 mM. The simple CAT/AuNPs/DMSA/Au system can be developed into a H 2 O 2 biosensor.