Electrochemical behavior of graphene/Nafion/Azure I/Au nanoparticles composites modified glass carbon electrode and its application as nonenzymatic hydrogen peroxide sensor

A novel nonenzymatic hydrogen peroxide sensor was developed using graphene/Nafion/azure I/Au nanoparticles composites modified glass carbon electrode (graphene/Nafion/AzI/AuNPs/GCE). The method of preparation of graphene/Nafion/AzI/AuNPs composite was simple and it was characterized by SEM. Cyclic voltammetry demonstrated that the direct electron transfer of redox molecule, Azure I, was realized, and the sensor had an excellent performance in terms of electrocatalytic reduction toward hydrogen peroxide (H2O2). The sensor showed high sensitivity and fast response upon the addition of H2O2, under the conditions of pH 4.0, potential −0.2 V. The time to reach the stable-state current was less than 3 s, and the linear range to H2O2 was from 30 μM to 5 mM with a detection limit of 10 μM (S/N = 3). Moreover, the sensor exhibited good reproducibility and long-term stability.