Buildup of polymer/Au nanoparticle multilayer thin films based on hydrogen bonding

We report two new hydrogen-bonding-based routes for layer-by-layer fabrication of polymer/Au nanoparticle multilayer thin films. Two types of Au nanoparticles surface-modified with carboxyl groups or pyridine groups were prepared in nonaqueous solvents. In the first assembly route, we consecutively adsorbed poly(4-vinylpyridine) (PVP) and Au nanoparticles with carboxyl group tailored surfaces. In the second route, we alternatively deposited poly(acrylic acid) (PAA) and Au nanoparticles with pyridine group tailored surfaces. The multilayer buildup was monitored by UV-vis spectroscopy, which showed a linear increase of the film absorbance with the number of adsorbed Au layers. FTIR spectroscopy was used to verify hydrogen bonding between the pyridine and carboxyl groups, which is believed to be the driving force for the formation of polymer/Au multilayer thin films.