The development of sensitive and convenient detection methods to monitor thrombin without the use of enzymes or complex nanomaterials is highly desirable for the diagnosis of cardiovascular diseases. In this article, tetraferrocene was first synthesized and then a sensitive and homogeneous electrochemical aptasensor was developed for thrombin detection based on host-guest recognition between tetraferrocene and β-cyclodextrin (β-CD). In the absence of thrombin, the double stem-loop of thrombin aptamer (TBA) prevented tetraferrocenes labeled at both ends from entering the cavity of β-CD deposited on gold electrode surface. After binding with thrombin, the stem-loop structure of TBA opened and transformed into special G-quarter structure, forcing tetraferrocene into the cavity of β-CD. As a result, thrombin allowed eight ferrocene molecules to reach the gold electrode surface, greatly amplifying the response signal. The obtained aptasensors showed dynamic detection range from 4 pM to 12.5 nM with detection limit around 1.2 pM. Overall, the results indicate that the proposed aptasensors are promising for future rapid clinical detection of thrombin and development of signal amplification strategies for detection of various proteins.

中文翻译：

---

基于四茂铁标记的高灵敏度宿主-客体模式均质电化学凝血酶信号放大适体传感器。

对于心血管疾病的诊断，非常需要开发一种灵敏且方便的检测方法来监测凝血酶而不使用酶或复杂的纳米材料。在本文中，首先合成了四茂铁，然后基于四茂铁与β-环糊精（β-CD）之间的客体识别，开发了一种敏感且均匀的电化学适体传感器，用于凝血酶检测。在没有凝血酶的情况下，凝血酶适体（TBA）的双茎环可防止两端标记的四茂铁进入沉积在金电极表面的β-CD腔。与凝血酶结合后，TBA的茎环结构打开并转变为特殊的G季度结构，迫使四茂铁进入β-CD腔。结果是，凝血酶使八个二茂铁分子到达金电极表面，大大放大了响应信号。所获得的适体传感器的动态检测范围为4 pM至12.5 nM，检测极限为1.2 pM左右。总体而言，结果表明，所提出的适体传感器对于凝血酶的未来快速临床检测以及用于检测各种蛋白质的信号放大策略的发展很有希望。