Manganese oxides/carbon nanowall nanocomposite electrode as an efficient non-enzymatic electrochemical sensor for hydrogen peroxide

Abstract

Plasma-enhanced chemical vapor deposition in a CO/H2 microwave discharge system was performed for synthesizing of carbon nanowalls template and subsequently potentiostatic anodic deposition technique was applied for depositing of manganese oxides onto the carbon nanowall surfaces. Characterization of the synthesized nanocomposite films was done via scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of MnOx/CNW electrode were investigated by cyclic voltammetry and amperometry techniques. The prepared nanocomposite electrode exhibited high electrochemical activity for the detection of hydrogen peroxide (H2O2) in phosphate buffer solution at an applied potential of +0.7 V, showing a linear dependence on the concentration of H2O2 from 40 μM to 10,230 μM, a high sensitivity (698.6 μA mM−1 cm−2), and a detection limit of 0.55 μM (signal/noise = 3). The sensor exhibited good selectivity toward hydrogen peroxide detection against ascorbic acid, uric acid, and citric acid. This study demonstrates a great potential of CNW based composite electrodes in nonenzymatic electrochemical sensor application.