Label-Free Analysis of Exosomes with Hairpin Structure-Mediated Multiple Signal Amplification Strategy.

Considering the crucial role of exosomes in various biological processes and disease diagnosis, development of label-free and sensitive exosome detection methods is in urgent demand. Herein, we develop an exponential amplification-based method pining the hope on sensitive exosomes detection in a label-free manner. In this method, a designed SMB (Streptavidin magnetic bead)-capture probe is utilized to specially recognize CD63 protein on the surface of exosome. The recognition of CD63 protein by SMB-capture probe induces the subsequent hairpin structure probe-mediated multiple signal amplifications. Eventually, the proposed approach can detect exosomes at a concentration as low as 1.2 × 10 particles/μl and can be potentially applied for clinical practices.