An oriented epitope-imprinted fluorescent sensor based on magnetic carbon dots for specific detection of CD47.

Cluster of differentiation 47 (CD47), a transmembrane glycoprotein overexpressed in various tumor cells, serves as an important immunoregulatory molecule and has emerged as a promising biomarker for disease diagnosis and therapeutic targeting. This research developed a magnetic fluorescent molecularly imprinted polymers (MMIPs)-based sensor for highly selective, sensitive, and rapid detection of CD47. The sensor was constructed by creating imprinted cavities on the surface of magnetic carbon dots (MCDs) through boronate affinity-oriented immobilization of a fructose-modified CD47 epitope, combined with zinc acrylate-assisted metal chelation. This oriented epitope imprinting strategy ensures precise control over template orientation, leading to improved binding site homogeneity and enhanced recognition performance. Under optimized conditions, the performance evaluation indicates that the sensor achieves a detection limit of 4.97 µmol L-1, coupled with excellent selectivity, a rapid response (20 min), and high accuracy in human serum samples (recovery rates of 96.4-101.6%). This platform thereby provides a reliable tool for CD47 detection in complex biological samples.