Electropolymerization of aniline onto passivated substrate and its application for preparation of enzyme-modified electrode

The electrodeposition of polyaniline film on an iron substrate electrode was studied for the preparation of an enzyme-modified electrode. The electrochemical polymerization of aniline was carried out using a passivated Fe substrate. The existence of a passive layer on the substrate surface has a significant effect on the formation of the electroactive film. Chronopotentiometric measurements were employed to investigate the influence of the passivated substrate on the electropolymerization process. The enzyme-modified electrodes were fabricated by incorporating glucose oxidase into the depositing polyaniline. Two different enzyme-electrodes using a conventional Fe electrode and a passivated Fe electrodes were prepared and compared. Experimental results illustrated that the polyaniline film formed on the passivated Fe electrode is highly stable and the approach proposed (using a passivated substrate) can be used to enhance stability of conductive polymer films. (C) 2004 Elsevier B.V. All rights reserved.