Electropolymerization of nano-dimensioned polypyrrole micro-ring arrays on gold substrates prepared using submerged micro-contact printing

Cobaltabisdicarbollide-doped polypyrrole (PPy-[Co(C2B9H11)(2)]) nanostructures have been produced by directed, potentiostatic electropolymerization using a patterned combination of conducting and insulating thiols (4-aminothiophenol and octadecylmercaptan, respectively). The different conducting characters of both self- assembled monolayers guides the PPy-[Co(C2B9H11)(2)] deposition over the pattern. In this way we have produced doped, nanostructured annular polypyrrole rings, similar to 400 nm high and similar to 200 nm wide at full width- half maximum height. Two processes are thought to affect the polypyrrole growth; primarily, the different conducting characters of the self- assembled thiol monolayers, but also the hydrophobic interactions between the electrolyte and the self- assembled monolayer. The effects of the hydrophobicity of the doping anion were also studied by comparing the microstructures obtained for polypyrrole doped with the lipophilic [Co(C2B9H11)(2)](-) anion and those doped with hydrophilic Cl- and ClO4- anions.