A Novel Hydrogen Peroxide Biosensor Based on the Synergistic Effect of Gold‐Platinum Alloy Nanoparticles/Polyaniline Nanotube/Chitosan Nanocomposite Membrane

Based on the immobilization of horseradish peroxidase (HRP) in chitosan(CS) on a glassy carbon electrode (GCE) modified with the Au-Pt alloy nanoparticles (NPs) / polyaniline nanotube (nanoPAN) nanocomposite film, a novel hydrogen peroxide biosensor was constructed. The modified processes of GCE were monitored by cyclic voltammetry and electrochemical impedance spectroscopy. Au-PtNPs/nanoPAN/CS had a better synergistic electrochemical effect than did AuNPs/nanoPAN/CS or PtNPs/nanoPAN/CS. The amperometric response of the biosensor towards H2O2 was investigated by successively adding aliquots of H2O2 to a continuous stirring phosphate buffer solution under the optimized conditions. Because Au-PtNPs have unique catalytic properties and good biocompatibility, and especially Au-PtNPs and nanoPAN have synergistic augmentation for facilitating electron-transfer, the biosensor displayed a fast response time (<2 s) and broad linear response to H2O2 in the range from 1.0 to 2200 μmol L−1 with a relatively low detection limit of 0.5 μmol L−1 at 3 times the background noise. Moreover, the biosensor can be applied in practical analysis and exhibited high sensitivity, good reproducibility, and long-term stability.