A sensitive nonenzymatic hydrogen peroxide sensor using cadmium oxide nanoparticles/multiwall carbon nanotube modified glassy carbon electrode

A simple sensing scheme for hydrogen peroxide has been described by electrochemical deposition of cadmium oxide (CdO) nanoparticles with similar to 50 nm in diameter on a glassy carbon (GC) electrode modified with multiwall carbon nanotubes (MWCNT). The CdO/MWCNT modified sensor, with a surface coverage of 1.13 x 10(-8) mol/cm(2), displayed high synergistic electrocatalytic activity for H2O2. The sensor was capable of reducing H2O2 at -1.2 V vs. Ag/AgCl (H2O2 + 2H(+)+ 2e(-) -> 2H(2)O) in a broad pH range. At the optimal pH 7, the sensor exhibited a detection limit of 0.1 mu M, broad linearity from 0.5 to 200 mu M, good reproducibility (RSD of 5.9%), and long-term stability. Uric acid, ascorbic acid and dopamine up to 100 mu M provoked no signal response, attesting selectivity of the CdO/MWCNT modified electrode for hydrogen peroxide. (C) 2014 Elsevier B.V. All rights reserved.