The properties of nanostructured electrodes prepared by the attachment of platinum nanoparticles to a gold electrode surface functionalized with a self-assembled monolayer of 1,8-diisocyanooctane have been investigated by reflectance infrared spectroscopy using the SNIFTIRS technique. The characteristic vibrations of the NC group have been observed both in the absence and in the presence of an attached nanoparticle layer. The bipolar bands observed indicate a potential dependent vibration, and this has been discussed in terms of the Stark effect and of the coordination chemistry of the isocyanide group attached to metal surfaces. The potential dependence of the NC vibration is similar to that observed for adsorbed CO. Coadsorption experiments using CO confirm unequivocally the presence of Pt on the film. Similar results have been obtained with palladium nanoparticles.