Gold Nanoparticulate Thin Films Fabricated by the Electrostatic Self—Assembly Process

Gold colloids were prepared by citrate-induced reduction of hydrogen tetrachloroaurate, and gold nanoparticles were electrostatically self-assembled with poly(diallyldimethylammonium chloride) into multilayer thin films on silicon and quartz substrates. The particulate thin films were characterized by UV-vis spectroscopy, surface enhanced Raman scattering, atomic force microscopy and resistivity measurements. Due to the interparticle coupling between individual gold particles,an obvious collective particle plasmon resonance was observed on UV-vis spectra, and the particulate thin films exhibited a strong SERS effect. For multilayer thin films with a high particle coverage on substrates, resistivity of the order of 10-4Ω*cm was yielded.