Hydrogen detection using surface plasmon resonance on palladium-siloxane films

We investigate the performance of Pd films on siloxane underlayer for the development of H₂ sensors based on the surface plasmon resonance (SPR) effect. Reflectance measurements were carried out on sputtered Pd films on bare glass and on glass pre-coated with a siloxane layer, using Kretschmann´s prism coupling configuration. For most of the range of Pd thicknesses investigated, the sensitivity for H₂ detection on bare glass was higher than that on Pd-siloxane, with the maximum sensitivity for the latter matching that on bare Pd. A direct comparison between the sensitivity data for the two multilayer configurations, indicates a trend of improved sensitivity for H₂ at higher thickness values for the siloxinated palladium films.