Homogenous Magneto-Fluorescent Nanosensor for Tumor-Derived Exosomes Isolation and Analysis.

Tumor-derived exosomes carrying unique surface proteins have shown great promise as novel biomarkers for liquid biopsies. However, point-of-care analysis for tumor-derived exosomes in blood with low-cost and easy processing is still challenging. Herein, we develop an integrated approach, homogenous Magneto-Fluorescent Exosome (hMFEX) nanosensor, for rapid and on-site tumor-derived exosomes analysis. Tumor-derived exosomes are captured immunomagnetically, which further initiates aptamer-triggered assembly of DNA three-way junctions in homogenous solution containing aggregation-induced emission luminogens and graphene oxide, resulting in an amplified fluorescence signal. By integrating magnetic isolation and enhanced fluorescence measurement, hMFEX nanosensor detects tumor-derived exosomes in the dynamic range spanning five orders of magnitude with high specificity, and the limit of detection is 6.56×104 particles/µL. Analyzing tumor-derived exosomes in limited volume plasma from breast can-cer patients demonstrates excellent clinical diagnostic efficacy of hMFEX nanosensor. This study provides new insights into the point-of-care testing of tumor-derived exosomes for cancer diagnostics.