Design and Analysis of a Biochemical Sensor Based on Surface Plasmon Resonance with Ultra-high Sensitivity

Abstract

We present a simple, unique, and highly sensitive surface plasmon resonance (SPR)-based photonic crystal fiber (PCF) biosensor. Besides having very high sensitivity, our proposed sensor is also fabrication friendly. The finite element method (FEM) of COMSOL 5.3a was utilized to devise the sensor’s structure and analyze the impact of changing geometric parameters on this biosensor’s overall performance. Gold (Au) or AZO (aluminum-doped zinc oxide) can be utilized to create excitation between the two modes (core and plasmonic). We have tried to vary different parameters of the PCF, and we observed in simulation results a very high amplitude sensitivity (AS) of 4358.09 RIU−1, maximum wavelength sensitivity (WS) of 21,000 nm/RIU (refractive index unit), a high figure of merits (FOM) of 729 with a sensor resolution of 4.76 × 10−6 RIU and 2.29 × 10−6 RIU for wavelength, and amplitude respectively when gold was utilized as the plasmonic material. Replacing gold by AZO resulted in the corresponding values of 3908 RIU−1, 1700 nm/RIU, 792, 5.88 × 10−5 RIU, and 2.56 × 10−6 RIU. Analyte refractive index (RI) ranges between 1.33–1.42 for gold and 1.31–1.39 for AZO. We believe the high performance of our proposed SPR based PCF biosensor in terms of sensitivity will bring a promising advancement in the field of unknown analyte detection and biological organic chemicals.