Review of the advances in lipid anchors-based biosensors for the isolation and detection of exosomes

Exosomes are nanoparticles with a bilayer lipid structure that carry cargo from their cells of origin. These vesicles are vital to disease diagnosis and therapeutics; however, conventional isolation and detection techniques are generally complicated, time-consuming, and costly, thus hampering the clinical applications of exosomes. Meanwhile, sandwich-structured immunoassays for exosome isolation and detection rely on the specific binding of membrane surface biomarkers, which may be limited by the type and amount of target protein present. Recently, lipid anchors inserted into the membranes of vesicles through hydrophobic interactions have been adopted as a new strategy for extracellular vesicle manipulation. By combining nonspecific and specific binding, the performance of biosensors can be improved variously. This review presents the reaction mechanisms and properties of lipid anchors/probes, as well as advances in the development of biosensors. The combination of signal amplification methods with lipid anchors is discussed in detail to provide insights into the design of convenient and sensitive detection techniques. Finally, the advantages, challenges, and future directions of lipid anchor-based exosome isolation and detection methods are highlighted from the perspectives of research, clinical use, and commercialization.