SPR Biosensor Based on Polymer PCF Coated With Conducting Metal Oxide

We propose a biosensor based on photonic crystal fiber made of polymethyl methacrylate using surface plasmon resonance. The proposed sensor consists of a layer of air holes as cladding and a central hole for phase matching between plasmon mode and core guided mode. Alternate holes in the second layer coated with conducting metal oxide, i.e., indium tin oxide (ITO), contain analyte. We found that the optimized thickness of the ITO for optimum performance is 70 nm, which matches with reported result. Unlike other metal coated structures, here the resonance is around telecommunication window and can be tuned by varying the intrinsic properties of the ITO as per requirement. The proposed sensor shows refractive index sensitivity as high as 2000 nm/RIU and has resolution of 5×10^-5 RIU.