INVESTIGATION OF ENHANCED SENSITIVITY IN TWO-DIMENSIONAL PHOTONIC CRYSTAL SENSOR PLATFORMS FOR APPLICATION IN CLINICAL DIAGNOSTICS

Abstract

This study investigates the enhancement of sensitivity in two-dimensional photonic crystal (2D PhC) sensor platforms for clinical diagnostics, with a specific focus on vitiligo detection. Vitiligo, an autoimmune depigmentation disorder, requires early and accurate diagnosis, yet current methods remain subjective and invasive. By engineering periodic dielectric architectures and introducing structural defects, 2D PhCs create localized resonant modes within the photonic bandgap that are highly sensitive to refractive index changes caused by cell's refractive index changes (Healthy and pigmented cells). Using finite difference time-domain (FDTD) simulations and plane wave expansion (PWE) methods, key parameters including the lattice constant, hole radius, quality factor (Q), and figure of merit (FoM) were optimized to maximize sensitivity. The results demonstrate a significantly enhanced sensing performance with a low detection limit, making the proposed platform a promising candidate for label-free, non-invasive, and point of-care vitiligo diagnostics. This work contributes to the broader application of photonic crystal biosensors in dermatological and clinical settings.