Surface plasmon resonance sensor with interchangeable optical element

摘要

A surface plasmon resonance (SPR) sensor includes a transparent base housing 12 and a detachable optical housing 19. Radiation from a radiation source 10, disposed within base housing 12, is polarized by polarizing filter 16 and passes through the interface between base housing 12 and optical housing 19. The polarized radiation 18 is reflected from a mirror 20 onto a SPR layer 22, which is formed on an exterior surface of optical housing 19. Layer 22 comprises a thin layer of a conductive material. Radiation 24 reflected from SPR layer 22 re-enters housing 19 and strikes an array 28 of photodetectors. From the intensity of radiation at each photodetector, one can determine the index of refraction of the substance on the opposite side of SPR layer 22.