文章基本信息

标题：Sensitive Identification of Microcystin-LR via a Reagent-Free and Reusable Electrochemical Biosensor Using a Methylene Blue-Labeled Aptamer
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作者：Xiaoqian Wei ; Shanlin Wang ; Yujuan Zhan 等
期刊名称：Biosensors
电子版ISSN：2079-6374
出版年度：2022
卷号：12
期号：8
DOI：10.3390/bios12080556
语种：English
出版社：MDPI Publishing
摘要：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.
关键词：microcystin-LR;methylene blue;aptamer;electrochemical sensor