New strategy to fabricate a polydopamine functionalized self-supported nanoporous gold film electrode for electrochemical sensing applications

Abstract

In this work, a polydopamine functionalized self-supported nanoporous gold film (PDA@NPGF) was prepared over a Au surface via anodization followed by chemical reduction method using dopamine as a reducing agent for the first time. Field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX) were used to characterize the surface morphology and for elemental analysis. The electrocatalytic activity and sensing ability of the PDA@NPGF platform were examined towards hydrogen peroxide (H2O2) and dopamine (DA) detection using cyclic voltammetry and amperometry techniques. Cyclic voltammetry results confirm the excellent catalytic activity of the PDA@NPGF electrode for H2O2 and DA sensing compared to that of bare Au, and nanoporous gold film (NPGF) electrodes. The electrochemical determination of H2O2 and DA at PDA@NPGF was evaluated by amperometry by applying a constant potential of −0.13 V and 0.20 V (vs. Ag/AgCl) in the linear range of 1–100 µM, respectively. The detection limit of the developed sensor for H2O2 and DA analysis was calculated using the corresponding calibration plots and the values were found to be 0.1 µM and 0.27 µM (S/N = 3), respectively. Keywords: Anodization, Nanoporous gold, Polydopamine, Electrochemical sensors, Hydrogen peroxide, Dopamine