An ultrasensitive electrochemical aptasensor for the determination of tumor exosomes based on click chemistry
An ultrasensitive electrochemical aptasensor for the determination of tumor exosomes based on click chemistry
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基于点击化学测定肿瘤外泌体的超灵敏电化学适体传感器
DOI：
10.1016/j.bios.2019.111503
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发表时间：
2019-10-01
影响因子：
12.6
通讯作者：
He, Pingang
中科院分区：
文献类型：
--
作者：
An, Yu;Jin, Tongyu;He, Pingang
外泌体是脂质双层膜泡，能指导各种病理生理过程。然而，可靠、方便、灵敏的外泌体检测方法在早期癌症诊断中仍然具有技术挑战性。本研究开发了一种基于click化学和DNA杂交链反应（HCR）信号放大的电化学配体传感器，用于肿瘤外泌体的超灵敏检测。首先将CD63适配体固定在玻璃碳电极上用于捕获外泌体，并通过氨基和醛基反应将功能化的脂质亲电试剂4-氧-2-壬烯醛炔（alkyyl -4- one）分子偶联到外泌体上。叠氮化物标记的DNA探针作为锚点，然后通过铜(I)催化的点击化学连接到外泌体上。HCR实现了信号放大，并且大量连接的辣根过氧化物酶（HRP）分子可以催化邻苯二胺（OPD）和H2O2的反应。通过监测2,3-二氨基吩嗪（DAP）的电化学还原电流，可以定量测定外泌体的浓度。在最佳条件下，该方法可在1.12 × 10(2) ~ 1.12 × 10(8)粒/ μ L范围内检测到外泌体，检出限（LOD）为96粒/ μ L。此外，该方法能够灵敏、准确地定量人血清中外泌体，在临床样品中分析外泌体具有很高的潜力。
Exosomes, lipid bilayer membrane vesicles, can guide various pathological and physiological processes. However, reliable, convenient and sensitive methods for exosome determination for early cancer diagnosis are still technically challenging. Herein, an electrochemical aptasensor based on click chemistry and the DNA hybridization chain reaction (HCR) for signal amplification has been developed for the ultrasensitive detection of tumor exosomes. CD63 aptamer was first immobilized on a glassy carbon electrode for capturing exosomes, and 4-oxo-2-nonenal alkyne (alkynyl-4-ONE) molecules, functionalized lipid electrophiles, were conjugated to the exosomes via the reaction of amino and aldehyde groups. Azide-labeled DNA probe as an anchor was then connected to the exosomes by copper (I)-catalyzed click chemistry. Signal amplification was achieved by HCR, and the numerous linked horseradish peroxidase (HRP) molecules could catalyze the reaction of o-phenylenediamine (OPD) and H2O2. The concentration of exosomes could be quantified by monitoring the electrochemical reduction current of 2,3-diaminophenazine (DAP). Under the optimal conditions, this method allowed the sensitive detection of exosomes in the range of 1.12 x 10(2) to 1.12 x 10(8) particles/mu L with a limit of detection (LOD) of 96 particles/mu L. Furthermore, the present assay enabled sensitive and accurate quantification of exosomes in human serum, and it has high potential for exosome analysis in clinical samples.