Exosomes that carry abundant information have attracted increasing attention as potent biomarkers of liquid biopsy and ideal candidates for early diagnosis and treatment of cancers. Shanghai University researchers propose a “principle-of-proof” biosensing method for amplified electrochemical detection of exosomes by using HepG2-derived exosomes as models. Specifically, target exosomes are enriched on anti-CD63-functionalized immunobeads and then recognized by a DNA chain containing CD63 aptamer region, which subsequently initiates a catalytic molecule machine that relies on cascade toehold-mediated strand displacement reaction. Benefiting from high efficiency of the molecule machine, the method shows a linear range from 1 × 105 to 5 × 107 particles/mL and a detection limit of 1.72 × 104 particles/mL toward target exosomes, better than most existing detection methods. Moreover, the method demonstrates a high specificity even in serum samples and suggests a potential use in clinic, which may provide sufficient information for disease diagnosis, especially early detection and prognosis monitoring of tumors.
A catalytic molecule machine-driven biosensing method for amplified electrochemical detection of exosomes
Cao Y, Li L, Han B, Wang Y, Dai Y, Zhao J. (2019) A catalytic molecule machine-driven biosensing method for amplified electrochemical detection of exosomes. Biosens Bioelectron [Epub ahead of print]. [abstract]