Electrocatalytic reduction of nitrite at polypyrrole nanowire-platinum nanocluster modified glassy carbon electrode

Pt nanoclusters were deposited in polypyrrole (PPy) nanowires by cyclic voltammetry method, fabricating a PPy-Pt nanocomposite on glassy carbon electrode (PPy-Pt/GCE). The electrocatalytic reduction of nitrite at PPy-Pt/GCE has been investigated using 0.5 M H2SO4 solution. The sensor exhibited excellent electrocatalytic activity toward nitrite reduction. In acidic medium, the cyclic voltammetry at 20 mV s(-1) gave a nitrite reduction peak at -0.124 V with 0.566 mu A mu M-1 current sensitivity in the range of 5.0 x 10(-7)-1.0 x 10(-3) M. The detection limit was 1.5 x 10(-7) M (s/n=3). The proposed method was successfully applied in the detection of nitrite in real water samples and obtained satisfactory results. The PPy-Pt composite modified electrode had good storage stability, reproducibility and anti-interference ability. (C) 2007 Elsevier B.V. All rights reserved.