Direct electron transfer between chloroperoxidase (CPO) from Caldariomyces fumago and gold electrode has been achieved by layer-by-layer adsorption of CPO and polydimethyldiallylammonium chloride (PDDA) monolayers on a gold electrode. QCM frequency shift demonstrated monolayer formed during each adsorption. Electrochemical characterization studies show thin layer properties of these PDDA-CPO-PDDA films. The PDDA-CPO-PDDA ultra-thin films were stable, up to 97% electrochemical activity remained after two days storage in phosphate buffer pH 5.