Label-free ochratoxin A electrochemical aptasensor based on target-induced noncovalent assembly of peroxidase-like graphitic carbon nitride nanosheet
Label-free ochratoxin A electrochemical aptasensor based on target-induced noncovalent assembly of peroxidase-like graphitic carbon nitride nanosheet
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DOI：
10.1016/j.snb.2018.05.048
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Xi Zhu;Fang Kou;Huifeng Xu;Yejian Han;Guidi Yang;Xiaojuan Huang;Wen Chen;Yuwu Chi;Zhenyu Lin
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文献类型：
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作者：
Xi Zhu;Fang Kou;Huifeng Xu;Yejian Han;Guidi Yang;Xiaojuan Huang;Wen Chen;Yuwu Chi;Zhenyu Lin
由于OTA具有严重的毒性，开发简单、快速、灵敏的OTA适体传感器对食品安全具有重要意义。本研究利用g-C3 N4纳米片（g-CNNS）固有的过氧化物酶样活性及其对信号链DNA的高亲和力，构建了一种无标记的电化学OTA适体传感器。与以前的基于g-CNNS的适体传感器相比，该适体传感器具有突出的性质，即不需要标记适体和固定g-CNNS。OTA的存在引起适配体的构象变化，使g-CNNS通过π-π相互作用与游离互补链在电极上非共价组装。捕获的g-CNNS催化H2 O2氧化，放大电流信号。结果表明，该适体传感器的检测限为0.073 nM，并用于检测真实的样品中的OTA，包括红葡萄酒，果汁和玉米。更重要的是，这种无标记的电化学适体传感器的开发开辟了g-CNNS作为过氧化物酶模拟DNA酶的应用。
The development of simple, fast and sensitive aptasensor for OTA plays an important role in food safety due to its severe toxicity. In this research, taking advantage of the intrinsic peroxidase-like activity of g-C3N4nanosheet (g-CNNS) and its high affinity toward signal-strand DNA, a label-free electrochemical OTA aptasensor was fabricated. There is an outstanding property that the aptasensor did not require labeled aptamer and immobilization of g-CNNS compared with previous g-CNNS-based aptasensors. The presence of OTA induced the conformational change of the aptamer, and then g-CNNS noncovalently assembled with the free complementary strand on the electrode via π-π interaction. The captured g-CNNS catalyzed the oxidation of H2O2to amplify current signal. As a result, this aptasensor realized the detection limit of 0.073 nM, and was also employed to assay OTA in the real samples, including red wines, juices and corns. More importantly, the development of this label-free electrochemical aptasensor opens up the application of g-CNNS as the peroxidase-mimicking DNAzyme.