Poly(ortho-phenylene diamine) synthesis enabled by the catalytic oxidase-like activity of nanoceria was accomplished for applications in electronics, medicine and biotechnology. The polymer shows unique morphology, conductivity and photoluminescence based on pH of the solution during synthesis. The various poly(ortho-phenylene diamine) preparations were characterized by UV-visible spectroscopy, scanning electron microscopy, fluorescence spectroscopy, fluorescence microscopy, high pressure liquid chromatography and cyclic voltammetry. Poly(ortho-phenylene diamine) synthesized at pH 1.0 by nanoceria was selected to be extensively studied based on the fast synthetic kinetics and the resulting conductive and photoluminiscent properties for various applications.