Magnetic Colloid Antibodies Accelerate Small Extracellular Vesicles Isolation for Point-of-Care Diagnostics.

Small extracellular vesicles (sEVs) are increasingly recognized as noninvasive diagnostic markers for many diseases. Hence, it is highly desirable to isolate sEVs rapidly for downstream molecular analyses. However, conventional methods for sEV isolation (such as ultracentrifugation and immune-based isolation) are time-consuming and expensive and require large sample volumes. Herein, we developed artificial magnetic colloid antibodies (MCAs) via surface imprinting technology for rapid isolation and analysis of sEVs. This approach enabled the rapid, purification-free, and low-cost isolation of sEVs based on size and shape recognition. The MCAs presented a higher capture yield in 20 min with more than 3-fold enrichment of sEVs compared with the ultracentrifugation method in 4 h. Moreover, the MCAs also proposed a reusability benefiting from the high stability of the organosilica recognition layer. By combining with volumetric bar-chart chip technology, this work provides a sensitive, rapid, and easy-to-use sEV detection platform for point-of-care (POC) diagnostics.