Copolymers derived from mixtures of pyrrole and N-(hydroxypropyl)pyrrole have been prepared electrochemically using various concentration ratios. Copolymers were generated on stainless electrodes by chronoamperometry and cyclic voltammetry in a LiClO4 acetonitrile solution. Relevant physical (density and doping level) and electrochemical (electroactivity and electrostability) properties of the copolymers have been examined and compared with those of the two corresponding homopolymers, which were prepared using the same electrochemical procedures. Results show that the copolymer obtained using the 25:75 N-(hydroxypropyl)pyrrole:pyrrole molar ratio presents an interesting behavior. Finally, the ability of the latter copolymer to form specific interactions with plasmid DNA has been compared with that of polypyrrole. © 2007 Springer Science+Business Media B.V.