AbstractA sensitive aptamer/protein binding-triggered sandwich assay for thrombin is described. It is based on electrochemical-chemical-chemical redox cycling using a glassy carbon electrode (GCE) that was modified with WSe2 and gold nanoparticles (AuNPs). The AuNPs are linked to thrombin aptamer 1 via Au-S bonds. Thrombin is first captured by aptamer 1 and then sandwiched through the simultaneous interaction with AuNPs modified with thrombin-specific aptamer 2 and signalling probe. Subsequently, the DNA-linked AuNP hybrids result in the capture of streptavidin-conjugated alkaline phosphatase onto the modified GCE through the specific affinity reaction for further signal enhancement. As a result, a linear range of 0–1 ng mL−1 and a detection limit as low as 190 fg mL−1 are accomplished. The specificity for thrombin is excellent. Conceivably, this strategy can be easily expanded to other proteins by using the appropriate aptamer. Graphical abstractSchematic presentation of an electrochemical biosensor for thrombin based on WSe2 and gold nanoparticles, aptamer-thrombin-aptamer sandwiching, redox cycling, and signal enhancement by alkaline phosphatase.

中文翻译：

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通过使用 WSe2 和金纳米粒子修饰的电极、适体-凝血酶-适体夹层、氧化还原循环和碱性磷酸酶增强信号对凝血酶进行超灵敏测定

摘要描述了一种灵敏的适体/蛋白质结合触发的凝血酶夹心测定法。它基于电化学-化学-化学氧化还原循环，使用用 WSe2 和金纳米粒子 (AuNPs) 改性的玻璃碳电极 (GCE)。AuNPs 通过 Au-S 键连接到凝血酶适体 1。凝血酶首先被适体 1 捕获，然后通过与用凝血酶特异性适体 2 和信号探针修饰的 AuNP 同时相互作用夹在中间。随后，DNA 连接的 AuNP 杂交体通过特定的亲和反应将链霉亲和素偶联的碱性磷酸酶捕获到修饰的 GCE 上，以进一步增强信号。结果，实现了 0–1 ng mL-1 的线性范围和低至 190 fg mL-1 的检测限。凝血酶的特异性非常好。可以想象，通过使用合适的适体，该策略可以很容易地扩展到其他蛋白质。图形摘要基于 WSe2 和金纳米粒子、适体-凝血酶-适体夹层、氧化还原循环和碱性磷酸酶增强信号的凝血酶电化学生物传感器的示意图。