Fabrication of gold nanocrystal-coated polypyrrole nanotubules

A method of fabricating gold nanocrystals coated polypyrrole (PPy) tubules was developed by coating carboxylic acid-thiol-capped or citrate-reduced gold nanoparticles on polypyrrole tubule templates. Electrostatic interaction between gold nanoparticles and PPy tubules was used as a driving force for this assembly process. The gold nanoparticle coated PPy tubule can be applied as signal-enhancing cuvettes for Raman spectroscopic analysis of trace molecules. The Raman scattering of trace Rhodamine B on the Au nanoparticle-coated tubule was enhanced by a factor of 10(4)-10(5).