Amperometric hydrogen peroxide biosensor based on cobalt ferrite–chitosan nanocomposite

A novel H2O2 biosensor based on horseradish peroxidase (HRP) immobilized into CoFe2O4–chitosan nanocomposite has been developed for the detection of hydrogen peroxide. The nanocomposite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). HRP has been entrapped into CoFe2O4–chitosan nanocomposite film and the immobilized enzyme could retain its bioactivity. This biosensor exhibited a fast amperometric response to hydrogen peroxide. The linear range for H2O2 determination was from 3 × 10− 2 to 8 mM, with a detection limit of 2 × 10− 3 mM based on S/N = 3. The response time of the biosensor was 4 s. The effects of the pH and the temperature of the immobilized HRP electrode were also studied.