Self-assembled gold nanoparticle/dendrimer composite films for vapor sensing applications

Vapor-sensitive thin-film resistors comprising gold nanoparticles and different types of organic dendrimers (polyphenylene, poly(propylene imine) and poly(amidoamine)) were prepared via layer-by-layer self-assembly and characterized by UV/vis spectroscopy, atomic force microscopy, and conductivity measurements, While the metal nanoparticles were utilized to provide the film material with electric conductivity, the dendrimers served to cross-link the nanoparticles and to provide sites for the selective sorption of analyte molecules. Dosing the films with vapors of toluene, 1-propanol, and water significantly increased the film resistances. The chemical selectivity of this response was controlled by the solubility properties of the dendrimers.