Optical Biosensing with Electromagnetic Surface Waves: SPP on Metals; Bloch Waves on Photonic Crystals

摘要

After its identification in the 1980s as a suitable optical transduction mechanism for gas sensing and biosensing, the surface plasmon resonance (SPR) effect found widespread commercial use for the latter sensing application in the early 1990s, when real-time, label-free, monitoring systems of biomolecular reactions started to reach the market. In this talk, the general properties of surface plasmons at a metal interface are described and the different approaches for observing the SPR effect are discussed, including planar, grating and fiber optic coupling schemes, with emphasis on biosensing applications. An analysis is presented on the key parameters that define the sensitivity of the effect for optical sensing. From this analysis, design parameters yielding maximum sensitivity in either planar or grating configurations are presented. Proposals for SPR, grating type, devices for operational normal incidence and Otto chip devices for biosensing with ultralow sample volumes are discussed.