A label-free aptasensor for the sensitive and specific detection of cocaine using supramolecular aptamer fragments/target complex by electrochemical impedance spectroscopy.
A label-free aptasensor for the sensitive and specific detection of cocaine using supramolecular aptamer fragments/target complex by electrochemical impedance spectroscopy.
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DOI：
10.1016/j.talanta.2012.01.049
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发表时间：
2012-04
期刊：
影响因子：
6.1
通讯作者：
De-Wen Zhang;Fang-ting Zhang;Yi-Ran Cui;Qin-pei Deng;S. Krause;Yinglin Zhou;Xinxiang Zhang
中科院分区：
文献类型：
--
作者：
De-Wen Zhang;Fang-ting Zhang;Yi-Ran Cui;Qin-pei Deng;S. Krause;Yinglin Zhou;Xinxiang Zhang
基于超分子适配体片段/底物复合物的形成，通过测量电化学阻抗谱（EIS）的变化，开发了一种简单、无标记的适配体传感器，用于灵敏、特异地检测可卡因。抗可卡因适体被分成两个片段，Cx和Cy。通过巯基化修饰Cx或Cy的5′端或3′端，再用巯基乙醇（MCE）处理，制备了Au/Cx 5 S/MCE、Au/Cy 3 S/MCE和Au/Cy 5 S/MCE三种不同的传感界面。通过监测[Fe（CN）6]3-/4-存在下的电化学阻抗谱，研究了相应的超分子适体片段/可卡因复合物的形成。界面电子转移电阻（Ret）被发现强烈依赖于可卡因浓度。由于超分子适配体片段/可卡因复合物在电极表面形成，传感界面强烈影响适配体传感器的灵敏度。Au/Cx 5S/MCE在0.1-20μM的可卡因检测范围内具有良好的灵敏度。此外，MCE被证明可以大大提高适体传感器的灵敏度。即使没有扩增或标记的帮助，低至100 nM的可卡因浓度也可以很容易地被开发的阻抗适体传感器检测到。并对可卡因适体传感器的特异性和再生性进行了研究，获得了满意的结果。所研制的适体传感器已成功应用于生物体液中可卡因的检测。
A simple and label-free aptasensor for sensitive and specific detection of cocaine was developed by measuring the change in electrochemical impedance spectra (EIS), based on the formation of a supramolecular aptamer fragments/substrate complex. An anticocaine aptamer was divided into two fragments, Cx and Cy. Three different sensing interfaces, called Au/Cx5S/MCE, Au/Cy3S/MCE and Au/Cy5S/MCE, were fabricated by immobilizing Cx or Cy on a gold electrode through modifying their 5′ or 3′ end with a thiolated group followed by the treatment with mercaptoethanol (MCE). The formation of the corresponding supramolecular aptamer fragments/cocaine complex was investigated via monitoring electrochemical impedance spectra in the presence of [Fe(CN)6]3−/4−. The interfacial electron transfer resistance (Ret) was found to depend strongly on the cocaine concentration. Since the supramolecular aptamer fragments/cocaine complex was formed on the electrode surface, the sensing interface strongly affected the sensitivity of the aptasensor. Au/Cx5S/MCE was shown to have good sensitivity within a cocaine detection range of 0.1–20μM. Moreover, MCE was shown to improve the sensitivity of the aptasensor greatly. Even without the help of amplification or labeling, cocaine concentrations as low as 100nM could be easily detected by the impedimetric aptasensor developed. The specificity and regeneration of the cocaine aptasensor were also investigated and satisfactory results were obtained. The developed aptasensor was successfully applied to detect the cocaine in biological fluids.