Emerging biosensing platforms for quantitative detection of exosomes as diagnostic biomarkers

Abstract Exosomes are a class of extracellular vesicles secreted by all living cells. Exosomes carry abundant constituents from their parental cells that are proteins, nucleic acids, lipids, small biomolecules, and metabolites. Recent studies have implied that exosomes are promising diagnostic biomarkers for a wide range of diseases, owing to their prominent features superior to other circulating biomarkers. Despite of the clinical potential of circulating exosomes for disease diagnostics, their translation from the bench to the bed-side has met substantive hurdles stemming from the lack of high-performance analytical technologies. Current research has focused on developing biosensors for exosomes from various sources in biomedical fields and addressed challenges that need to be solved before their practical applications in the clinic and point-of-care (POC) fields. Functional nanostructures have been integrated into these emerging biosensing platforms with improved performances, allowing for molecular profiling and quantitative analysis of exosomes. This article provides a comprehensive overview regarding recent advances of new biosensing platforms for detection of exosomes. We will focus on the rational design, working principles and exosome-based diagnostic applications of these emerging biosensors. This review will expectedly provide valuable guidelines for the further development of biosensors for practical applications of exosomes in the clinic and POC diagnostics.