SILICON-BASED SURFACE-PLASMON RESONANCE CHEMICAL SENSORS

A silicon-based surface plasmon resonance (SPR) technique has been suc cessfully applied to NO2 sensing at ppm level using devices with uncoa ted and phthalocyanine-coated gold films. Surface-enhanced Raman scatt ering (SERS) has been used as an additional data-acquisition channel c apable of providing spectroscopic selectivity and amplified sensitivit y. Reversible responses of both SERS and SPR-induced photosignals prod uced by Au-on-Si grating structures coated with thin 18-crown-6 H(2)pc phthalocyanine films are simultaneously recorded for exposures of the films to 10 ppm of NO2 in air. Possible sensing applications are disc ussed.