Recent scientific investigations have highlighted the carcinoembryonic antigen's (CEA) critical role in diagnosing and monitoring various cancers, including liver, colon, breast, and colorectal cancers. Elevated levels of CEA in human serum are associated with these malignancies, measuring CEA concentrations essential for effective cancer prevention and diagnosis. This research has developed a sophisticated two-dimensional)2D( materials-based surface plasmon resonance (SPR) optical sensor utilizing a Kretschmann configuration. This innovative sensor incorporates multiple layers, such as a BK7 prism, gold (Au), MXene (Ti3C2Tx), molybdenum trioxide (MoO3), black phosphorus (BP), and molybdenum disulfide (MoS2) to enhance its detection capabilities for CEA in aqueous solutions. The performance of this SPR sensor is rigorously analyzed using the finite difference time domain (FDTD) numerical solution method, which allows for precise evaluations of its sensitivity and other critical parameters. At a wavelength of 633 nm, the sensor's performance metrics include sensitivity, figure of merit (FOM), detection accuracy (DA), detection limit (DL), signal-to-noise ratio (SNR), and severity rating (SR). Notably, the sensor achieved a remarkable sensitivity of 196.91 deg/RIU and a FOM of 14.87 RIU-1, indicating significant improvements over previous designs. Comparative analyses reveal that this SPR biosensor outperforms earlier models in terms of sensitivity, positioning it as a promising alternative for applications in biosensing, food safety monitoring, medical diagnostics, and environmental assessments. The advancements in this research underscore the potential for SPR technology to provide rapid and accurate detection of CEA levels, thereby contributing to more effective cancer management strategies.