A Hydrogen Peroxide Biosensor Based on Direct Electrochemistry of Hemoglobin in Palladium Nanoparticles/Graphene–Chitosan Nanocomposite Film

摘要

Thermally two-dimensional lattice graphene (GR) and biocompatibility chitosan (CS) act as a suitable support for the deposition of palladium nanoparticles (PdNPs). A novel hydrogen peroxide (H₂O₂) biosensor based on immobilization of hemoglobin (Hb) in thin film of CS containing GR and PdNPs was developed. The surface morphologies of a set of representative membranes were characterized by means of scanning electron microscopy and showed that the PdNPs are of a sphere shape and an average diameter of 50 nm. Under the optimal conditions, the immobilized Hb showed fast and excellent electrocatalytic activity to H₂O₂ with a small Michaelis–Menten constant of 16 μmol L−1, a linear range from 2.0 × 10−6 to 1.1 × 10−3 mol L−1, and a detection limit of 6.6 × 10−7 mol L−1. The biosensor also exhibited other advantages, good reproducibility, and long-term stability, and PdNPs/GR–CS nanocomposites film would be a promising material in the preparation of third generation biosensor.