A Third‐Generation Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized in Carbon Nanotubes/ SBA‐15 Film

Abstract

Abstract A new third‐generation biosensor for H 2 O 2 assay was developed on the basis of the immobilization of horseradish peroxidase (HRP) in a nanocomposite film of carbon nanotubes (CNTs)‐SBA‐15 modified gold electrode. The biological activity of HRP immobilizing in the composite film was characterized by UV‐vis spectra. The HRP immobilized in the nanocomposite matrix displayed excellent electrocatalytic activity to the reduction of H 2 O 2 . The effects of the experimental variables such as solution pH and working potential were investigated using steady‐state amperometry. Under the optimal conditions, the resulting biosensor showed a linear range from 1 µM to 7 mM and a detection limit of 0.5 µM ( S / N =3). Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.