A label-free homogeneous electrochemical aptasensor was developed for detection of thrombin based on proximity hybridization triggered hybridization chain reaction induced G-quadruplex formation. Thrombin promoted the formation of a complex via the proximity hybridization of the aptamer DNA strands, which unfolded the molecular beacon, the stem part of molecular beacon as a primer to initiate the hybridization chain reaction process. Thus, with the electrochemical indicator hemin selectively intercalated into the multiple G-quadruplexes, a significant electrochemical signal drop is observed, which is dependent on the concentration of the target thrombin. Thus, using this“signal-off” mode, label-free homogeneous electrochemical strategy for sensitive thrombin assay with a detection limit of 44 fM is realized. Furthermore, this method also exhibits additional advantages of simplicity and low cost, since both expensive labeling and sophisticated probe immobilization processes are avoided. Its high sensitivity, acceptable accuracy, and satisfactory versatility of analytes led to various applications in bioanalysis.

基于邻近杂交触发的杂交链反应诱导的G-四链体形成，开发了一种无标记的均质电化学适体传感器，用于检测凝血酶。凝血酶通过适体DNA链的邻近杂交促进复合物的形成，其使分子信标展开，分子信标是分子信标的茎部分，用作引发杂交链反应过程的引物。因此，在电化学指示剂血红素选择性地插入多个G-四链体中的情况下，观察到显着的电化学信号下降，这取决于目标凝血酶的浓度。因此，使用这种“信号关闭”模式，可以实现检测限为44 fM的灵敏凝血酶测定的无标记均相电化学策略。此外，由于避免了昂贵的标记和复杂的探针固定过程，该方法还显示出简单和低成本的其他优点。它的高灵敏度，可接受的准确性和令人满意的分析物多功能性导致了生物分析的各种应用。