Description
This research presents a photonic crystal fiber (PCF) based surface plasmon resonance (SPR) biosensor illuminated by a supercontinuum laser source and numerically investigated using the finite element method (FEM) in COMSOL Multiphysics 6.2 for cancer cell detection through refractive index (RI) variations.
The sensor numerically incorporates a gold (Au) and titanium dioxide (TiO2) plasmonic layer on a fabricated-on silica platform. The influence of plasmonic layer thickness and air-hole dimensions on confinement loss (CL), wavelength sensitivity (WS), and amplitude sensitivity (AS) is systematically analysed.
Results show that excessive Au thickness can increases CL while reducing sensitivity due to limited evanescent-field penetration. Geometrical variations (±10%) in air-hole dimensions also significantly affect sensor performance, highlighting the need for structural optimization. The optimized sensor achieves a maximum WS of 31,000 nm/RIU and 29,500 nm/RIU under x- and y polarization, respectively, with resolutions down to 3.22 × 10⁻⁶ RIU and AS exceeding 9000 RIU⁻¹, demonstrating strong potential for ultrasensitive early cancer detection.
