基于固着微液滴的外泌体microRNA即时检测

外泌体microRNA（miRNA）广泛存在于各种体液中，与肿瘤的发生、发展密切相关，是一种潜在的非侵入性肿瘤标志物。外泌体miRNA囊泡内原位检测无需复杂的分离、裂解等前处理步骤，通过将检测探针转入外泌体内即可实现一步检测，在肿瘤即时检测中表现出巨大的优势。而检测探针的有效转染及外泌体富集仍是影响外泌体miRNA原位即时检测性能的关键因素。此外，实际样品中存在的循环miRNA及其他细胞外囊泡miRNA会对检测结果产生干扰。基于此，本项目拟利用固着微液滴蒸发驱动的Marangoni效应提高检测探针的转染效率，利用浓缩富集效应进一步提高检测灵敏度；利用特异性识别外泌体的细胞膜对检测探针进行封装，避免实际样品中循环miRNA及其他细胞外囊泡miRNA对检测结果准确性的干扰。本项目构建的传感策略无需对样品进行预处理，即可实现外泌体miRNA高灵敏、高通量、准确、即时检测，为肿瘤诊断提供了新思路。

Exosomal microRNA (miRNA) is widely present in different bodily fluids and associated with the occurrence and development of tumors, which is considered as a potential non-invasive tumor biomarker. The in-situ detection of exosomal miRNA can be achieved in one-step by transferring detection probe into exosome, which doesn’t need any complicated pretreatment procedures including exosome isolation, exosome lysis and shows great potential in point-of-care diagnosis of tumors. The effective transfection of detection probe and the enrichment of exosomes are two key factors to affect the detection performance of the biosensor for in-situ detection of exosomal miRNA. Moreover, when detecting exosomal miRNA in real sample, the circulating miRNA and miRNA in other extracellular vesicles will affect the detection results of exosomal miRNA. In this project, Marangoni effect induced by the evaporation of sessile microdroplet are applied to improve the transfection efficiency and the enrichment effect are further applied to improve the detection sensitivity. The detection probe is protected by the cell membrane which can specifically recognize the exosomes, and thus the accuracy of the detection results would not be influenced by the circulating miRNA and the miRNA in other extracellular vesicles in the real biological samples. The project can achieve point-of-care detection of exosomal miRNA with high sensitivity, high-throughput and accuracy without complicated sample pretreatment, which provides a powerful method for early diagnosis of tumors.