Nanostructured Electrochemical Sensor Based on Dense Gold Nanoparticle Films

Polyelectrolyte (PE)/gold nanoparticle hybrid films that can be utilized as efficient electrochemical sensors were prepared by infiltrating 4-(dimethylamino)pyridine-stabilized gold nanoparticles (DMAP−AuNP) into PE multilayers preassembled on indium tin oxide (ITO) electrodes. Quartz crystal microgravimetry (QCM) and UV−vis spectroscopy showed that via this infiltration method, composite films with densely packed DMAP−AuNP were obtained. Electrochemical experiments revealed that the presence of gold nanoparticles in the PE multilayers could significantly improve the electron-transfer characteristics of the films, which showed high electrocatalytic activity to the oxidation of nitric oxide (NO). The sensitivity of the composite films for measuring NO could be further tailored by controlling the gold nanoparticle loading in the film.