Xiang Ya School of Public Health, Central South University, Changsha 410078, China.
Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha 410078, China.
Biosensors (Basel). 2022 Jul 22;12(8):556. doi: 10.3390/bios12080556.
We report a methylene blue (MB)-modified electrochemical aptamer (E-AB) sensor for determining microcystin-LR (MC-LR). The signal transduction of the sensor was based on changes in conformation and position of MB induced by the binding between MC-LR and the modified aptamer probe. In the absence of MC-LR, an aptamer probe was considered partially folded. After combining aptamer and MC-LR, the configuration of the aptamer probe changed and facilitated the electron transfer between MB and the electrode surface. As a result, an increased current response was observed. We optimized the parameters and evaluated the electrochemical performance of the sensor using square wave voltammetry (SWV). MC-LR was measured from 1.0 to 750.0 ng/L with a detection limit of 0.53 ng/L. The reliability of the method was verified by the determination of MC-LR in environmental real samples, such as pond water and tap water. Moreover, we demonstrated that this reagent-less biosensor could be regenerated and reused after rinsing with deionized water with good accuracy and reproducibility. As a reusable and regenerable E-AB sensor, this rapid, reagent-free, and sensitive sensing platform will facilitate routine monitoring of MC-LR in actual samples.
我们报告了一种亚甲蓝（MB）修饰的电化学适体（E-AB）传感器，用于测定微囊藻毒素-LR（MC-LR）。该传感器的信号转导基于 MC-LR 与修饰的适体探针结合引起的 MB 构象和位置变化。在没有 MC-LR 的情况下，适体探针被认为是部分折叠的。在适体和 MC-LR 结合后，适体探针的构象发生变化，促进了 MB 和电极表面之间的电子转移。因此，观察到电流响应增加。我们使用方波伏安法（SWV）优化了参数并评估了传感器的电化学性能。MC-LR 的检测范围为 1.0 至 750.0 ng/L，检测限为 0.53 ng/L。通过对池塘水和自来水等环境实际样品中 MC-LR 的测定，验证了该方法的可靠性。此外，我们证明，这种无试剂的生物传感器可以在用水冲洗后再生和重复使用，具有良好的准确性和重现性。作为一种可重复使用和再生的 E-AB 传感器，这种快速、无试剂、灵敏的传感平台将有助于实际样品中 MC-LR 的常规监测。
