Abstract: An atomic force microscope(AFM) was used to observe enzyme topology on a multilayer enzyme/polyelectrolyte film on structured trans parent indium-tin oxide(ITO) covered glass electrode surface. The multilayer film was prepared by alternate electric field directed layer-by-layer assembly d eposition， the alternate deposition of glucose oxidase and polyelectrolyt e poly (diallyldimethyl-ammonium chloride) (PDDA) on ITO glass electrode surface . Also, from the atomic force microscopic measurements, the more information of the multilayer constructed by different methods on the modified electrode sur face was obtained and compared. Under a low applied voltage, enzyme molecules exist on the film in cluster form, while in an aggregate form under a high a pplied voltage.

Key words: AFM, electric field induce, multilayer film, topology