Dengue disease detection via a minimal area 2D photonic crystal nanocavity-based refractive index optical biosensor: numerical analysis

Despite advancements in optical biosensing technologies, existing methods for detecting dengue-infected blood components often lack the sensitivity and precision required for early diagnosis, emphasizing the necessity of better sensor designs. A compact photonic crystal nanocavity-based optical sensor has been designed to detect dengue-infected blood components. The simulation is performed using the finite-difference time-domain numerical technique with a Gaussian source. The transmission spectrum and corresponding resonance shifts have been analyzed to evaluate the proposed sensor's performance. Utilizing the C-band (1550 to 1600 nm) optical source, the sensor system has been designed and numerically analyzed to detect dengue-infected blood components. The geometrical parameter of the nanocavity is also optimized with variation in the number of silicon rods and their radii to maximize the device detection sensitivity. The results demonstrate that a maximum sensitivity of 899 nm/RIU and a quality factor of 711 are achieved. The figure of merit and detection limit have been calculated as and , respectively. We have compared our proposed sensor with the previous designs from the literature, demonstrating improved sensitivity, lower detection limits, and a more compact footprint with . These enhancements suggest that our device can outperform state-of-the-art sensors to the best of the authors' knowledge.