Novel Hydrogen Peroxide Sensor Based on Chitosan-Ag Nanoparticles Electrodeposited on Glassy Carbon Electrode

Abstract

A sensitive, simple and economically cheap hydrogen peroxide (H₂O₂) sensor was developed by electrodepositing Ag nanoparticles in the presence of chitosan on a glassy carbon electrode (GCE). Atomic force microscopy results showed that the Ag nanoparticles was small as compared to Ag nanoparticles on bare GCE and exhibited a narrow size distribution. The electrochemical experiments showed that this chitosan-Ag nanoparticles/GCE had a good catalytic ability toward the reduction of H₂O₂. The effects of deposition potential, deposition time to the concentration of chitosan for Ag nanoparticles formation and the pH of the electrolyte solution on the electrocatalytic reduction of H₂O₂ were also investigated. Under the optimal conditions, the sensor exhibited a linear range of 1.0 μM to 8.6 mM with the detection limit of 0.24 μM. A rapid response of the sensor could achieve 95 % of the steady-state current in less than 2 s. This sensor with a high selectivity and sensitivity was expected to use for practical applications in detecting H₂O₂.