Poly(Celestine Blue)-Graphene Oxide Nanohybrid Modified Electrode for Amperometric Determination of Hydrogen Peroxide

This work describes and validates an electrochemical approach for H2O2 determination using Poly(celestine blue)/graphene oxide modified graphite electrode. Electrochemical characterization and electrocatalytic behaviour of the graphene oxide-poly(celestine blue) modified electrode towards the reduction of hydrogen peroxide were studied using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. It was demonstrated that poly(celestine blue) acts as a mediator for electrocatalytic reduction of H2O2 while graphene oxide enhances the electron transfer between the electrode and H2O2. Various parameters influencing the electrochemical behaviour of the modified electrode were optimized. The modified electrode showed a distinct redox peak of poly(celestine blue) at the scan rate of 50 mV/s in 0.1 M of NH4NO3 (pH 7). The linear range of determination was found to be from 3.33 x 10(-6) M to 1.30 x 10(-3) M with detection limit of 1.11x10(-6) M (S/N = 3) and with a sensitivity of 0.1627 mu A/mu M. The modified electrode showed comparatively good sensitivity and increased current response for the determination of hydrogen peroxide.