Facile Preparation of High-Performance Copper Oxide Sensors for Electroanalysis of Hydrogen Peroxide

Abstract

We report on the template electrodeposition of different copper/copper oxide nanoparticles on pencil graphite lead substrate using ionic and neutral surfactant templates. Physical structure and electrochemical properties of the modified electrodes were shown to be influenced by the nature of surfactant template. These copper modified pencil graphite electrodes exhibited very good catalytic activity towards hydrogen peroxide reduction reaction, which could be used for the sensitive and selective detection of H2O2. A maximum sensitivity of ca. 158 µA/mM/cm2, lower limit of detection (LOD) of 0.35 ± 0.04 µM, response time of <2 seconds and a linearity in wide range of concentration from 1 µM to 13 mM were observed. These electrodes were highly selective towards hydrogen peroxide with little interference from glucose, fructose, ascorbic acid, dopamine, uric acid, urea, chlorides, nitrates and sulphates even at 100 fold higher concentrations of the interfering species compared to H2O2 concentration. Practical feasibility of the sensor was demonstrated by detecting H2O2 in human blood serum and milk samples with good recovery. Our methodology enables one to prepare the electrode within two minutes and to complete the analysis within another 60 seconds, enabling the quantitative detection of hydrogen peroxide in less than five minutes using a freshly prepared, cost-effective electrode without any complicated procedure.