Non-enzymatic Reduction of Hydrogen Peroxide Sensor Based on (Polyaniline-polystyrene Sulphonate) - Carboxylated Graphene Modified Graphite Electrode

A modified electrode is fabricated by the electrodeposition of polyaniline-polystyrene sulphonate composite onto the carboxylated graphene modified graphite electrode for the detection of hydrogen peroxide (H 2O2). The modified electrode displayed excellent catalytic response to the reduction of hydrogen peroxide in neutral pH. It was found that the presence of carboxylated graphene in the sensor system could effectively increase the electron transfer rate and stability. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. Chronoamperometric studies showed the linear relationship between the reduction peak current and the concentration of H 2O2 in the range 25 to 350 µM ( R = 0.995) with the detection limit of 1×10 -6 mol/L ( S/N =3). Further, electrochemical analysis of H 2O2 in the presence of common interferents such as dopamine, uric acid and ascorbic acid with the modified electrode reveals that there is no overlapping signal from the interferents.