Recent advances in exosome analysis assisted by functional nucleic acid-based signal amplification technologies

The sensitive and accurate analysis of exosomes is of great significance because they contain the original bioactive molecules of their parent cells, which are closely associated with the pathogenesis of various diseases. Among various technologies developed for the detection of exosomes, the ones integrated with functional nucleic acid (FNA)-based signal amplification strategies have emerged to be powerful tools. In this review, we present the recent advances in exosome analysis based on the FNA-assisted signal amplification technologies, including the nucleic acid extension strategies, the DNA machines, the emerging CRISPR/Cas systems, and the digital assay methods, and discuss the design principles, the assay performance, as well as the unique features of these FNA-based exosome analysis methods in detail. We have also prospected that the development of microfluidic devices and artificial intelligence will further promote the high-throughput and multi-parameter profiling of exosomes, which will lead the future trend of exosome-based clinical diagnosis.