Buildup of polymer/Au nanoparticle multilayer thin films based on hydrogenbonding

We report two new hydrogen-bonding-based routes for layer-by-layer fabricat ion of polymer/Au nanoparticle multilayer thin films. Two types of Au nanop articles surface-modified with carboxyl groups or pyridine groups were prep ared in nonaqueous solvents. In the first assembly route, we consecutively adsorbed poly(4-vinylpyridine) (PVP) and Au nanoparticles with carboxyl gro up tailored surfaces. In the second route, we alternatively deposited poly( acrylic acid) (PAA) and Au nanoparticles with pyridine group tailored surfa ces. The multilayer buildup was monitored by UV-vis spectroscopy, which sho wed 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.