A Novel Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized on Poly(aniline-co-o-aminobenzoic acid) Modified Glassy Carbon Electrode Coated with Chitosan Film

In this work, a novel amperometric biosensor for hydrogen peroxide (H2O2) determination was successfully prepared by immobilizing horseradish peroxidase (HRP) on poly(aniline-co-o-aminobenzoic acid) or p(Ani-co-o-Aba) and then covered with chitosan (CS) film. The immobilized HRP displayed an excellent electrocatalytic activity to the reduction of hydrogen peroxide. The effects of experimental variables such as the o-Aba mol ratios in p(Ani-co-o-Aba) synthesis, HRP and CS concentrations, pHs of supporting electrolyte solution and applied potentials for the working electrode were investigated for the optimized conditions. This novel biosensor exhibits a fast response toward H2O2 with a linear range from 10 to 1,000 mu M and a detection limit of 1.8 mu M based on the signal-to-noise ratio (S/N = 3). The developed biosensor shows satisfactory tolerance with other potential interferences such as dopamine (DA), ascorbic acid (AA), glucose (Glu) and uric acid (UA), and also shows a good stability for similar to 2 weeks.