Electrocatalytic oxidation of ascorbic acid at polypyrrole nanowire modified electrode

Polypyrrole (PPy) nanowire modified electrodes were prepared electrochemically by template-free method based on graphite electrodes. The freshly prepared electrodes were dipped in 10% HClO4 solution at least 24h for removal of carbonate ions. The modified electrodes toward ascorbic acid were characterized by potentiostatic method. The experiment's results show that the PPy modified electrodes have obvious electrocatalytic effect toward ascorbic acid oxidation. The oxidation current density has a good linearity in the concentration range of 5.0 x 10(-4) and 2.0 x 10(-2) mol L-1 of ascorbic acid. The determination sensitivity may be significantly affected by the thickness of PPy film and pH of the test solution. The method has promising application in determination of ascorbic acid in the real samples. (c) 2006 Elsevier B.V. All rights reserved.