Numerical investigation of PCF-based biosensor for pathologies detection in blood

A photonic crystal fiber (PCF) based surface plasmon resonance (SPR) biosensor has been proposed for detecting the concentration of albumin (ALB), urea, glucose, and hemoglobin (Hb) in blood samples. The sensor features a square lattice PCF design with an optimized plasmonic gold coating, ensuring strong light-matter interaction for enhanced sensitivity. The finite element method (FEM) is employed to numerically evaluate the sensor's performance, analyzing wavelength sensitivity (WS), signal-to-noise ratio (SNR), detection limit (DL), and confinement loss. The proposed sensor achieves a maximum WS of 20,000 nm/RIU for detecting ALB (600–1000 mg/dL) and urea (2.5 g/dL), while glucose and Hb detection reach 10,000 nm/RIU and 5000 nm/RIU, respectively. Additionally, the sensor exhibits an exceptionally low DL and strong linear response, demonstrating its feasibility for high precision biosensing. With its high sensitivity, compact structure, and simplified fabrication, this PCF-SPR biosensor presents a robust, label-free, and real-time diagnostic tool for biomedical and clinical applications. This work establishes a foundation for future experimental validation and integration into point-of-care healthcare systems.