Highly Sensitive PCF Sensor Based on Au-TiO₂ for Cancer Cell Detection

This study introduces a bilaterally polished D-shaped surface plasmon resonance (SPR) sensor based on Au-TiO2 for early detection of cancer cells. The refractive indices of the six different types of normal and cancer cells detected ranged from 1.36 to 1.401. The finite element method is used for numerical analysis. The spectral interrogation method is used to detect the refractive index variations of cancer cells. According to numerical results, blood cancer has the highest wavelength sensitivity (23643 nm/RIU) in the structure of the optimal parameters. The wavelength sensitivities for the rest of the cancer cells are 10150 nm/RIU for skin cancer basal cells, 18291 nm/RIU for cervical cancer HeLa cells, 20642 nm/RIU for adrenal gland cancer PC 12 cells, 13142 nm/RIU for breast cancer type 1 MDA-MB-231 cells, and 9142 nm/RIU breast cancer type 2 MCF-7 cells. Moreover, the FOM reaches a maximum of 382.28/RIU with a maximum resolution of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.23\times 10^{-{6}}$ </tex-math></inline-formula> RIU. Compared to related studies, the sensor design exhibits superior sensitivity, resolution, and figure of merit, making it highly beneficial for medical applications in cancer detection.