A conductive polymer is formed enzymatically in the presence of a polynucleotide template. The method includes combining at least one redox monomer with a polynucleotide template and a redox enzyme, such as horseradish peroxidase, to form a reaction mixture. The monomer aligns along the template before or during the polymerization. Therefore, the polynucleotide template thereby affects the molecular weight and conformation of the conductive polymer. When the conductive polymer is complexed to a polynucleotide duplex, the conformation of the polynucleotide duplex can be modulated by changing the oxidation state of the conductive polymer.