Preparation and Characterization of a RedoxMultilayer Film Containing Au Nanoparticles

Gold nanoparticles encapsulated by negatively charged molecules have been stably anchored at a Au substratethrough layer-by-layer deposition technique, employing a redox polyviologen derivative as the cationiccounterpart. UV-vis spectroscopy, quartz crystal microbalance, transmission electron microscopy, scanningelectron microscopy, atomic force microscopy, and voltammetric measurements have been performed in orderto characterize the systems and to give a rationale to the effect of the deposition conditions on the propertiesof the resulting multilayers. The behavior of two benchmark electroactive species ([Fe(CN)6]4- and[Ru(NH3)6]3+) has been studied on nanoparticle-terminated multilayers. The nanoparticles provide chargepercolation through the multilayer and charge transfer with redox species in solution. The results imply thatthe electrochemical behavior of nanoparticle-containing films is partly dependent on the charge compensationmode within polyelectrolyte multilayers.