Horseradish peroxidase has been demonstrated to catalyze the oxidative polymerization of aniline to form conductive polyaniline. This process is facilitated by the presence of a macromolecular template with sulfonic acid groups that provide a unique environment for the formation of the conducting polymer, Here we report the use of a photo-cross-linkable thymine-based polymer with phenylsulfonate, groups as a templating substrate, This allows for an aqueous-based environmentally benign photopatterning of a conductive material. A description and results of this process are presented.