A photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is to obtain maximum sensitivity for the detection of unknown analytes. Chemically stable and inactive plasmonic material gold (Au) is used outside of the PCF structure. To evaluate the performance of the sensor, a perfectly match layer (PML) is also added for diminishing the unwanted nonphysical radiation. The proposed sensor is consists of double layer symmetrical square air holes. A small air hole in the center is used to produce the more evanescent field. Sensing performance is numerically investigated by the finite element method (FEM) based on commercially available tools COMSOL Multiphysics. The maximum amplitude sensitivity of this proposed sensor is 442.11 RIU−1 with the highest sensor resolution 1.66 × 10−5 using amplitude integration method. The wavelength sensitivity is 6000 nm/RIU using amplitude integration method. The proposed sensor is widely applicable in bio-photonics applications.
