The oxidative polymerization of 3,3'-diaminobenzidine (DAB) on gold electrode and in various solvents was studied by cyclic voltammetry, SEM and IR spectroscopy. Cyclic voltammetry studies show that, DAB is oxidized to a rather stable cation (DAB(+)) in a one electron transfer process. Effect of the electrolytic conditions on the stability of the radical cations was studied. The polymers prepared in acidic aqueous solution and organic solvents are electroactive and show finite diffusion and thin layer cell behavior at sweep rates lower than 0.500 V s(-1) respectively. As it can be seen from infrared spectra and also the ability of polymer to form a stable complex selectively with SE(W) in solutions, the polymer is containing free amine groups. The stripping current of complexed selenium on to the polymer is diffusion controlled and the SEM photographs show the polymer prepared in organic solvents is more compact and then the rate of diffusion of selenium ions is lower than that in polymer prepared in aqueous solution. (c) 2005 Elsevier B.V. All rights reserved.