Study of Nitric Oxide Sensors Based on Nafion/Phosphotungstic Heteropolyacid/Polypyrrole Modified Glassy Carbon Electrodes

Abstract

A Nafion/phosphotungstic heteropolyacid/polypyrrole modified glassy carbon electrode (Nf/PW12/PPY/GCE) was prepared in this paper. The electrochemical behaviours of nitric oxide at the Nf/PW12/PPY/GCE were investigated by cyclic voltammetry. The experimental results indicated that the phosphotungstic heteropolyacid doped in polypyrrole film possessed obvious catalysis for the electroxidation of nitric oxide. In 0.1mol/L sulfuric acid, the anodic peak current of nitric oxide at the sensors linearly increased with nitric oxide concentration over the range of 1.0×10-7～2.5×10-5mol/L with a detection limit of 3.0×10-8mol/L. The Nafion layer modified on the surface of electrocatalyst could effectively eliminate the inferences from common species in biological samples such as ascorbate, uric acid and nitrite. The presented methods of determing nitric oxide exhibited high sensitivity and good reproducibility.