Different sensing layers for SPR sensing of organic vapours

In this work we present a theoretical and experimental work due to develop a performing configuration for gas-sensing through the employ of Surface Plasmon Resonance effect. Different sensing layers have been studied and tested on our optical bench assembly. Metallic (Au) and bimetallic (Ag/Au) layers have been properly designed through simulations and then have been realized through electron-beam evaporation. TiO2 and TiO2 - Au doped layers have been deposited on the top of some of the metallic samples. These layers were prepared by the sol gel route. This kind of material is expected to be suitable as a gas sensor for its nanosized structure and its stability. The optical bench configuration for the experimental exploitation of SPR is presented. It is based on a collimated beam, a rotational stage with a triangular prism and a single photodiode. Finally the sensing properties of the different sensing layers prepared was tested to some organic vapours. Preliminary results are presented.