Advancements in Nanostructure Engineering: A Wheel-Shaped High-Sensitivity Surface Plasmon Resonance Refractive Index Sensor for Enhanced Analyte Detection and Sensing Applications

This study performed an extensive investigation into the performance exploration of Photonic Crystal Fiber refractive index sensors based on Surface Plasmon Resonance (SPR-PCF). Numerical investigation of the sensor's properties was performed using the Finite Element Method (FEM) in COMSOL Multiphysics software. Thin coatings of titanium dioxide (TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) and gold (Au) enhanced sensor performance by acting as plasmonic materials around the PCF. The proposed sensor detected unknown layer of analytes along the refractive index (RI) that ranges from 1.33 to 1.42. After optimization of different parameters, the proposed PCF-SPR sensor showed an outstanding performance by achieving a maximum Amplitude Sensitivity (AS) of 1998.9892 RIU<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. Also, a highest wavelength sensitivity (WS) of 25,000 nm/ RIU, and a notable figure of merit (FOM) of 531.915 RIU<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, demonstrated its accuracy and effectiveness. This design exhibited a favorable sensing performance by achieving higher wavelength sensitivity, better sensor resolution, and simplicity of fabrication. Furthermore, the proposed sensor will be significant in scientific, biological, and industrial domains and may be used for multi-sensing applications like temperature sensing, magnetic field detecting, etc.