Design and optimization of a hybrid SPR biosensor for highly sensitive detection of carcinoembryonic antigen

Carcinoembryonic antigen (CEA) serves as a key biomarker that is widely utilized for diagnosing and monitoring various cancers, especially those affecting the liver, breast, and colon. The strong association between elevated CEA concentrations in human serum and these malignancies emphasizes the importance of accurate measurements for early diagnosis and effective cancer management. This study introduces a new hybrid plasmonic design that combines graphene with a MgO+Ag+ZnSe multilayer stack, resulting in superior field confinement and enhanced sensor performance compared to conventional SPR biosensors. The synergy of these materials and the multi-method computational evaluation provide a powerful, highly accurate platform for CEA detection. The device employs the Kretschmann configuration and introduces a novel multilayer architecture consisting of a CaF2 prism, magnesium oxide, silver, zinc selenide, and a graphene interface. The evaluation of the sensor’s sensitivity and overall performance indices was conducted using three computational techniques, such as the finite element method (FEM), the finite-difference time-domain (FDTD) simulations, and the transfer matrix method (TMM). The proposed device achieved a sensitivity of 385.08 deg./RIU, a figure of merit of 78.52 and quality factor of 85.99 RIU−1 at an operating wavelength of 633 nm. In essence, this study underscores the significant potential of SPR-based biosensing, offering a powerful and precise platform for CEA detection, offering meaningful advancements in cancer diagnostics and clinical management.