Early Detection and Screening of Bladder Cancer Based on a Novel Optical Fiber Surface Plasmon Resonance Sensor

Bladder cancer (BC) poses significant health threats that include high rates of recurrence, potential metastasis, and impaired urinary function. Biomarker testing is a noninvasive and urine-based method, which offers higher sensitivity in early detection and recurrence monitoring. A novel optical fiber (OF) sensor based on surface plasmon resonance (SPR) technology was presented for noninvasive detection of BC biomarkers such as nuclear matrix protein 22 (NMP22) with real-time monitoring and high sensitivity. NMP22 antibody, as a specific recognition substance of the biosensor, was immobilized on the surface of gold film using a chemical crosslinking method to prepare OF sensing probes. Under optimum preparation conditions, immunoreactivity between NMP22 and antibody shows a strong correlation with drift of the SPR peak. The SPR-based OF sensor demonstrated effective detection of NMP22 in real urine samples, exhibiting excellent reproducibility, stability, and selectivity. Comparative analysis with the standard enzyme-linked immunosorbent assay (ELISA) revealed that this OF sensor offers comparable analytical performance, suggesting its strong potential for noninvasive clinical applications.