Tetrahedral DNA mediated direct quantification of exosomes by contact-electrification effect

Abstract Exosomes are membrane-enclosed extracellular vesicles carrying multiple biomolecules for intercellular communications. Accurate detection of exosomes could provide critical clinical information and show great significance for early diagnosis and personalized therapy of cancer. In this work, we propose a triboelectric sensing strategy for direct quantification of exosomes based on the contact-electrification effect. The target exosomes can be selectively captured on the three-dimensional tetrahedral DNA (TDNA) monolayer. The electrons transfer between abundant amino groups from exosomes and the tribo-materials contribute to the measured signal. Due to the specific output characteristic, it is able to directly discriminate 3 exosomes /μL with a linear range from 20 to 1000 exosomes/μL, even without any signal amplification. The challenges for distinguishing different cell line-derived exosomes and anti-interference in complicated biological serum systems show good performances. The presence of target exosomes can also be easily determined by visual observation of LED lighted by the generated electric energy. The proposed method can be used as a powerful tool for ultrasensitive analysis of exosomes, which is expected to have broad biological and analytical applications.