A highly selective electrochemical impedance spectroscopy-based aptasensor for sensitive detection of acetamiprid
A highly selective electrochemical impedance spectroscopy-based aptasensor for sensitive detection of acetamiprid
复制标题
一种基于电化学阻抗谱的高选择性适体传感器，用于灵敏检测啶虫脒
DOI：
10.1016/j.bios.2012.11.033
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发表时间：
2013-05-15
影响因子：
12.6
通讯作者：
Li, Zhengxin
中科院分区：
文献类型：
--
作者：
Fan, Lifang;Zhao, Guohua;Li, Zhengxin
基于电化学交流阻抗技术，研制了一种简单、灵敏、选择性检测啶虫脒的适体传感器。为了提高适体传感器的灵敏度，金纳米粒子（AuNPs）通过循环伏安法（CV）电沉积在裸金电极表面，这是作为一个平台的适体固定。随着啶虫脒的加入，啶虫脒-适体复合物在金纳米粒子沉积电极表面上的形成导致电子传递电阻（R-et）的增加。R-et的变化强烈依赖于啶虫脒的浓度，其被用于啶虫脒定量。在5 ~ 600 nM范围内线性关系良好，检测限为1 nM。通过使用可能与啶虫脒共存或具有类似结构的农药进行的对照实验证明，适体传感器仅对啶虫脒具有特异性识别，从而导致适体传感器的高选择性。通过假设朗缪尔等温线，从微分电容（C-d）确定了啶虫脒适体复合物的解离常数K-d为23.41 nM，这表明啶虫脒和适体之间存在强相互作用，进一步证明了适体传感器的高选择性。通过对真实的样品、废水和番茄中啶虫脒的测定，验证了该传感器的适用性。(c)2012爱思唯尔有限公司版权所有。
A simple aptasensor for sensitive and selective detection of acetamiprid has been developed based on electrochemical impedance spectroscopy (EIS). To improve sensitivity of the aptasensor, gold nanoparticles (AuNPs) were electrodeposited on the bare gold electrode surface by cycle voltammetry (CV), which was employed as a platform for aptamer immobilization. With the addition of acetamiprid, the formation of acetamiprid-aptamer complex on the AuNPs-deposited electrode surface resulted in an increase of electron transfer resistance (R-et). The change of R-et strongly depends on acetamiprid concentration, which is applied for acetamiprid quantification. A wide linear range was obtained from 5 to 600 nM with a low detection limit of 1 nM. The control experiments performed by employing the pesticides that may coexist or have similar structure with acetamiprid demonstrate that the aptasensor has only specific recognition to acetamiprid, resulting in high selectivity of the aptasensor. The dissociation constant, K-d of 23.41 nM for acetamiprid aptamer complex has been determined from the differential capacitance (C-d) by assuming a Langmuir isotherm, which indicates strong interaction between acetamiprid and aptamer, further proving high selectivity of the aptasensor. Besides, the applicability of the developed aptasensor has been successfully evaluated by determining acetamiprid in the real samples, wastewater and tomatoes. (c) 2012 Elsevier B.V. All rights reserved.