Design of a high-sensitivity 2D photonic crystal refractive index sensing platform for biological fluid analysis
摘要
This work presents the design and numerical analysis of a two-dimensional photonic crystal (2D-PhC) biosensor platform for refractive-index sensing of biological fluids such as urine and blood. The proposed platform integrates three vertically aligned ring-shaped microcavities within a silicon photonic crystal structure optimized to operate near the 1550 nm resonance. The device was evaluated using refractive-index values for biological samples associated with glucose concentration, high-density lipoprotein (HDL) cholesterol, sickle cell anemia, and HIV infection. The sensing mechanism is based on monitoring shifts in the resonant wavelength caused by variations in the refractive index when biological analytes infiltrate the microcavities. The structure is modeled and simulated using RSoft Photonic Suite CAD environment.
Simulation results demonstrated that the proposed biosensor achieves a sensitivity exceeding 1100 nm/RIU. With a Q-factor on the order of 106, a figure of merit (FoM) of approximately 106 RIU−1, and a limit of detection close to 10−7 RIU. These results indicate that the proposed photonic crystal platform can serve as a compact, label-free, and non-invasive sensor for high-sensitivity refractive index sensing in biological fluids.