School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, China.
Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, 250022, China.
Mikrochim Acta. 2022 Aug 15;189(9):332. doi: 10.1007/s00604-022-05424-0.
A strand displacement-based "signal-off" electrochemical aptasensor is reported for the detection of Mucin 1 (MUC 1) based on a high original signal. Different from the conventional "signal-off" electrochemical biosensors where electrochemical substances are dispersed in electrolyte solution, here the current signal was generated by the complementary probe (CP) associated with ferrocene (Fc) labeled aptamer (Apt.-Fc). Because Apt.-Fc and MUC 1 have a higher affinity, Apt.-Fc dissociates from CP in the presence of MUC 1, resulting in a reduction of detection current signal generated by oxidation of labeled Fc. In this system, high detection signal is necessary to improve the sensor's performance. For this aim, a strategy is proposed for changing the modalities of electron transport and the quantity of Apt.-Fc introduced by simply tuning the sequence constitution of CP. As expected, a high detection current signal was obtained after selecting CP(Apt.-Fc)-TTT as the optimal CP. The aptasensor was then employed to detect MUC 1, and satisfactory detection results with a low detection limit (LOD) of 0.087 pM (S/N = 3), good specificity, good stability, and feasibility of detection of MUC 1 in artificial serum (recovery of 92-101%, RSD of 1.36-5.23%) were obtained.
基于高原始信号，报道了一种基于链置换的“信号关闭”电化学适体传感器，用于检测黏蛋白 1（MUC 1）。与传统的“信号关闭”电化学生物传感器不同，这里的电流信号是由与二茂铁（Fc）标记的适体（Apt.-Fc）相关联的互补探针（CP）产生的。由于 Apt.-Fc 和 MUC 1 具有更高的亲和力，在存在 MUC 1 的情况下，Apt.-Fc 从 CP 上解离，导致标记的 Fc 氧化产生的检测电流信号减少。在这个系统中，需要高的检测信号来提高传感器的性能。为此，提出了一种通过简单调整 CP 序列组成来改变电子传输方式和引入 Apt.-Fc 数量的策略。正如预期的那样，选择 CP(Apt.-Fc)-TTT 作为最佳 CP 后，获得了高的检测电流信号。然后，该适体传感器用于检测 MUC 1，并获得了令人满意的检测结果，具有低检测限（LOD）为 0.087 pM（S/N = 3）、良好的特异性、良好的稳定性和在人工血清中检测 MUC 1 的可行性（回收率为 92-101%，RSD 为 1.36-5.23%）。
