Accurate identification of exosomes based on proximity-induced autonomous assembly of DNAzyme wires

Exosomes are extracellular vesicles that transport different kinds of molecular information, and exosome identification is crucial for non-invasive illness detection and therapy. Therefore, the development of simple, sensitive, and specific assays for exosome identification is highly demanding. In this paper, we developed a proximity-induced autonomous assembly of DNAzyme wires (PIAA-DNAzyme wires) for accurate identification of exosomes. The hybridization chain reaction (HCR) and DNAzyme are combined to enable isothermal dual amplification. Moreover, interference from free proteins would be reduced using proximity mediated HCR by simultaneous recognition of surface proteins and lipid membranes. The results show that the detection limit of exosomes was 2.5 × 103 particles/μL under the optimum conditions. Single-step exosome identification with excellent sensitivity and high anti-interference was achieved. The proposed strategy could offer an advantageous platform for precise exosome recognition and early disease detection.