This study presents the design and theoretical analysis of a pseudo parity-time symmetric photonic crystal biosensor for early oral cancer detection. Using the transfer matrix method, we numerically investigated the resonant transmission properties of a 1D photonic crystal structure with a central defect layer (D = 50 μm) containing healthy and cancer oral cells. The proposed \(\:{\left(Si{O}_{2}*Si\right)}^{N}\left(oral\:cells\right){\left(Si{O}_{2}*Si\right)}^{N}*substrate\) configuration exhibits exceptional sensitivity, quantified by two key metrics: a spectral sensitivity of 118 GHz/RIU and an extraordinary transmittance sensitivity of \(\:1.9\times\:{10}^{8}\:\%/RIU.\) These results demonstrate significant improvements over conventional photonic biosensors, enabled by the PT-symmetric design’s ability to operate near an exceptional point. The optimized structure achieves ultra-sharp resonances ( \(\:9.1\times\:{10}^{-5}\) THz FWHM) with remarkable field enhancement, making it particularly suitable for detecting minute refractive index changes associated with malignant transformations. Our findings establish a foundation for developing high-performance, label-free diagnostic tools for early-stage oral cancer detection.
