Extracellular vesicles (EVs), namely, exosomes and microvesicles, are important mediators of intercellular communication pathways. Since EVs can be detected in a variety of biofluids and contain a specific set of biomarkers which are reminiscent of their parental cells, they show great promise in clinical diagnostics as EV analysis can be performed in minimally invasive liquid biopsies. However, reliable, fast and cost-effective methods for their determination are still needed, especially if decentralized analysis is intended. In this study, we developed an electrochemical biosensor which works with 1.5 μL sample volume and can detect as low as 200 exosomes per microliter, with a linear range spanning almost 4 orders of magnitude. The sensor is specific and readily differentiates exosomes from microvesicles in samples containing 1000-fold excess of the latter. Capability of detecting exosomes in real samples (diluted serum) was shown. This was achieved by immobilizing rabbit antihuman CD9 antibodies on gold substrates and using monoclonal antibodies against CD9 for detection of captured exosomes. Signal amplification is presumably obtained from the fact that multiple detector antibodies bind to the surface of each captured vesicle. Detection is performed based on electrochemical reduction of 3,3',5,5'-tetramethyl benzidine (TMB) after addition of horseradish peroxidase (HRP)-conjugated anti-IgG antibodies. This amperometric biosensor can be easily incorporated into future miniaturized and semiautomatic devices for EV determination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.