Highly Sensitive Determination of Hydrogen Peroxide Employing Copper Nanoparticles Decorated Neutral Red Film on a Glassy Carbon Electrode

Hydrogen peroxide (H2O2) is a very simple molecule in nature but has been widely used in pharmaceutical, clinic, environmental, mining, textile, paper, food manufacturing and chemical industries because of its strong oxidizing and reducing properties [1, 2]. This work describes a convenient and effective strategy to construct a highly sensitive amperometric biosensor for the detection of H2O2 based on neutral red (NR) and Cu nanoparticles (CuNPs) nano composite. Scanning electron microscope (SEM) image showed that the neutral red have been electropolymerized on the GCE and the Cu nanoparticles were immobilized as spherical particles on the polymer surface. The electrochemical performance of the sensor for detection of H2O2 was investigated by cyclic voltammetry and chronoamperometry techniques. The modified electrode exhibits an enhanced electrocatalytic property, low working potential, high sensitivity, excellent selectivity, good stability, and fast amperometric sensing of hydrogen peroxide. The detection limit of the electrochemical sensor using the CuNPs/PNR/GCE for H2O2 determination was calculated to be 1.5×10-7 M, which was even superior to some noble metal-decorated H2O2 sensors. The effective coupling of NR and CuNPs boosted significantly the electroanalytical performance by providing more active area for analyte interaction, thereby allowing more rapid interfacial electron transfer process. These studies revealed that the novel Cu NPs/PNR/GCE sensor could be a potential candidate for the detection of H2O2.