Non-Enzymatic Amperometric Sensing of Hydrogen Peroxide Based on Vanadium Pentoxide Nanostructures

Herein, a simple and selective electrochemical sensor was proposed for non-enzymatic determination of hydrogen peroxide (H2O2). This sensor was fabricated by incorporation of the novel nanostructured orthorhombic vanadium pentoxide (V2O5) into the carbon paste electrode (CPE) which provides significant catalytic activities for H2O2 reduction. The electrochemical impedance spectroscopy (EIS) studies illustrated lower charge transfer resistance (R-ct) of the V2O5 modified CPE compared to the unmodified CPE. The effects of various experimental factors such as solution pH, applied potential and amount of modifier were studied in an amperometric mode. After optimization, the proposed method displayed a wide linear detection range from 5.0 to 1400.0 mu M with a low detection limit of 2.5 mu M based S/N = 3 and a response time less than 5 s. The sensitivity of 3.44 mu A mu M-1 cm(-2) was acquired in the present method for H2O2 quantification is considerably better than other reported amperometric sensors with similar detection limits. In addition, the designed sensor depicted good reproducibility, remarkable selectivity, and excellent stability. The modified CPE was applicable for analysis of H2O2 in some cosmetic and personal care products. (C) 2019 The Electrochemical Society.