An optofluidics biosensor consisted of high-finesse Fabry-Perot resonator and micro-fluidic channel

A high quality factor Fabry-Perot cavity (FPC) biosensor with smooth and flat micro-channel surface is realized by using a silicon on insulator substrate, in which the oxide layer functions as an etch-stop layer. The measured quality factor and sensitivity of the FPC biosensor are 861 and 1100 nm/RIU (refractive index units), respectively, and the corresponding detection limit (DL) reaches 1.1 x 10(-5) RIU. Moreover, due to the smooth and flat channel surface, higher quality factor and better DL can be obtained with increasing reflectivity of the Bragg reflector of the FPC biosensor. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726188]