Polyaniline nanowire synthesis templated by DNA

Abstract

DNA-templated polyaniline nanowires and networks are synthesized using three differentmethods. The resulting DNA/polyaniline hybrids are fully characterized using atomic forcemicroscopy, UV–vis spectroscopy and current–voltage measurements. Oxidativepolymerization of polyaniline at moderate pH values is accomplished using ammoniumpersulfate as an oxidant, or alternatively in an enzymatic oxidation by hydrogen peroxideusing horseradish peroxidase, or by photo-oxidation using a ruthenium complex asphoto-oxidant. Atomic force microscopy shows that all three methods lead to thepreferential growth of polyaniline along DNA templates. With ammonium persulfate,polyaniline can be grown on DNA templates already immobilized on a surface.Current–voltage measurements are successfully conducted on DNA/polyaniline networkssynthesized by the enzymatic method and the photo-oxidation method. The conductanceis found to be consistent with values measured for undoped polyaniline films.