Highly Sensitive PCF-SPR RI Sensor for Cancer Detection Using Gold/Graphene/Ti₃C₂T_x-MXene Hybrid Layer

In this paper, a gold/graphene/Ti₃C₂T_x-MXene hybrid layered D-type photonic crystal fiber (PCF) design based on surface plasmon resonance (SPR) sensors is proposed for cancer cell detection. This design uniquely combines gold, graphene, and Ti₃C₂T_x-MXene materials to achieve a synergistic effect, significantly enhancing the sensitivity and specificity of the sensor. The full vector finite element method (FVFEM) is used for the entire numerical analysis of the proposed biosensor. The cladding of the D-type PCF has a hexagonal arrangement of air holes. In the first cladding, the two air holes closest to the metal layer are narrowed down to enhance the plasma wave and provide an efficient leakage channel. The last two air holes closest to the metal layer in the same layer are enlarged to limit light scattering and couple more energy to the surface plasmon polariton (SPP) mode. The sensitivity of the sensor improves by using these different diameter air holes and coating the D-type PCF surface with a hybrid gold/graphene/Ti₃C₂T_x-MXene layer. The geometrical parameters are optimized to obtain higher sensor sensitivity. The corresponding wavelength sensitivities are 3000 nm/RIU for Basal cells, 5000 nm/RIU for HeLa cells (Henrietta Lacks cells), 5714 nm/RIU for Jurkat cells (Human T lymphocyte cells), 7143 nm/RIU for PC12 cells (Pheochromocytoma cells), 8571 nm/RIU for MDA-MB-231 cells (Breast cancer cells), and 9286 nm/RIU for MCF-7 cells (Michigan Cancer Foundation-7, a breast cancer cell line), respectively, confirming the excellent performance of the proposed sensor. The sensor proposed paves the way for efficient, simple, low-cost, and highly sensitive cancer detection techniques that could replace surgical and chemical techniques.