A Numerical Analysis of Rectangular Open Channel Embedded TiO2-Au-MXene Employed PCF Biosensor for Brain Tumor Diagnosis

In this work, a surface plasmon resonance (SPR) plasmonic photonic crystal fiber (PCF) biosensor embedded with a rectangular open channel (ROC) is proposed, enabling precise detection and discrimination between healthy and tumorous brain tissues. Healthy and tumorous tissues are considered liquid tissues, each possessing its own distinctive refractive index (RI). The ROC is coated with gold (Au) to generate surface plasmons. To facilitate ample biomolecules, a thin Ti3C2Tx-MXene layer is functionalized over Au. A thin titanium dioxide (TiO2) layer is coated on the ROC surface to strongly hold the Au nanoparticles, ensuring improved sensing performance. Healthy, cancerous, and tumor tissue samples exhibit unique resonance wavelengths, allowing for their diagnosis through the measurement of shifts in their respective resonance wavelengths. The essential performance parameters, including sensitivity (S), full-width at half-maximum (FWHM), and figure of merit (FoM), are evaluated. The computed sensitivities for normal and abnormal tissues, i.e., gray matter, cerebrospinal fluid, and oligodendroglioma are 12352.94, 2030.45, and 672.26 nm/refractive index unit (RIU), respectively, measured with respect to white matter and the wall of a solid brain. And, for tumorous tissues (cancers and tumors) such as glioblastoma, lymphoma, and metastasis, the sensitivities are 800, 774.9, and 643.26 nm/RIU, respectively, measured with respect to low-grade glioma (Benign). Additionally, the proposed biosensor's resolution (R) ranges from {1}.{25}\times {{10}}^{-{4}} to {8}.{09}\times {{10}}^{-{6}} RIU along with the maximum FoM of 126.05 RIU−1. Hence, this biosensor is poised to excel in the detection of tumor and cancer tissues, making it a promising candidate for advancing medical diagnostics.