Label-free Aptasensor Based on Imaging Weak Measurement for Ovarian Cancer Detection

Accurate measurement of the glycoprotein antigen CA125 is critical for early detection of ovarian cancer, given its widespread recognition as an FDA-approved tumor biomarker. In this study, we developed a total reflective biosensor based on imaging weak measurement, utilizing aptamers as the key recognition element for CA125 detection. Leveraging the aptamer's attributes of high stability, simple synthesis, and easy modification, we employed a polydopamine membrane modification technique to immobilize the aminated aptamer onto the prism surface. The label-free aptasensor was evaluated through light intensity measurements, demonstrating a detection range from 0.1 U/mL to 200 U/mL and achieving a notable resolution of 0.083 U/mL. In addition, the method specifically recognizes CA125 without interference from other proteins. In conclusion, the imaging weak measurement-based aptamer biosensor offers a straightforward, rapid, highly sensitive, and cost-effective approach for detecting CA125 in practical applications.