Graphene oxide-Cu(II) composite electrode for non-enzymatic determination of hydrogen peroxide

We report a novel graphene oxide-Cu(II) (GO-Cu 2+) composite electrode for electrochemical determination of hydrogen peroxide (H 2 O 2) in neutral solution (pH = 7.4). Oxygen functional groups such as carboxylic acid, hy-droxyl and epoxy present on GO are utilized for the formation of composite with Cu 2+ ions. The synthesized GO-Cu 2+ composite was characterized by X-ray diffraction (XRD) studies and cyclic voltammetry (CV). The surface morphology of the GO and GO-Cu 2+ composite materials was observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Elemental analysis was performed using EDS. The prepared electrode showed a good electrocatalytic performance for reduction of H 2 O 2 and mechanistic pathway has been discussed. Amperometric determination for H 2 O 2 was carried out at a applied potential of −0.25 V vs Ag/AgCl and the result showed a linear response range of 5 μM to 85 μM (correlation coefficient = 0.999) with a detection limit of 0.5 μM (S/N = 3). The sensitivity of the electrode was found to be 0.072 μA μM −1 and the electrode selectively detected H 2 O 2 in the presence of other potential interferences such as oxygen, glucose, ascorbic acid (AA), dopamine (DA) and uric acid (UA).