Highly Sensitive and Selective Immuno-Capture/Electrochemical Assay of Acetylcholinesterase Activity in Red Blood Cells: A Biomarker of Exposure to Organophosphorus Pesticides and Nerve Agents
Highly Sensitive and Selective Immuno-Capture/Electrochemical Assay of Acetylcholinesterase Activity in Red Blood Cells: A Biomarker of Exposure to Organophosphorus Pesticides and Nerve Agents
复制标题
红细胞中乙酰胆碱酯酶活性的高灵敏和选择性免疫捕获/电化学测定：有机磷农药和神经毒剂暴露的生物标志物
DOI：
10.1021/es202689u
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发表时间：
2012-02-07
影响因子：
11.4
通讯作者：
Lin, Yuehe
中科院分区：
文献类型：
--
作者：
Chen, Aiqiong;Du, Dan;Lin, Yuehe
红细胞乙酰胆碱酯酶（AChE）活性是生物监测有机磷农药和化学神经毒剂暴露的一种有用的生物标志物。本文报道了一种基于选择性免疫捕获生物样品中乙酰胆碱酯酶活性的新方法，然后使用一次性电化学传感器对捕获的乙酰胆碱酯酶活性进行测定。该电化学传感器是基于多壁碳纳米管-金（MWCNTs-Au）纳米复合材料修饰的丝网印刷碳电极（SPCE），用于固定化乙酰胆碱酯酶特异性抗体。免疫反应完成后，靶AChE（包括活性的和抑制的）被捕获到电极表面，然后在乙酰硫代二醇存在下进行酶活性的电化学检测。在0.1 ~ 10 nM的标准乙酰胆碱浓度范围内得到线性响应。为了证明这种新的生物监测方法的能力，用不同浓度对氧磷的乙酰胆碱酯溶液来验证新的乙酰胆碱酯酶测定方法。在0.2 ~ 50 nM范围内，OP溶液对AChE的抑制作用与OP浓度成正比。新的乙酰胆碱酯酶活性测定方法用于OP暴露的生物监测，进一步验证了体外对氧磷剂量的RBC样本。建立的乙酰胆碱酯酶活性测定电化学传感平台，既避免了选择性抗体与酯酶底物特异性重叠的问题，又消除了生物样品中其他电活性物质的潜在干扰。为有机磷暴露的生物监测提供了一种灵敏、选择性、快速的乙酰胆碱酯酶活性测定方法。
Acetylcholinesterase (AChE) enzyme activity in red blood cells (RBCs) is a useful biomarker for biomonitoring of exposures to organophosphorus (OP) pesticides and chemical nerve agents. In this paper, we reported a new method for AChE activity assay based on selective immuno-capture of AChE from biological samples followed by enzyme activity assay of captured AChE using a disposable electrochemical sensor. The electrochemical sensor is based on multiwalled carbon nanotubes-gold (MWCNTs-Au) nanocomposites modified screen printed carbon electrode (SPCE), which is used for the immobilization of AChE specific antibody. Upon the completion of immunoreaction, the target AChE (including active and inhibited) is captured onto the electrode surface and followed by an electrochemical detection of enzymatic activity in the presence of acetylthiodioline. A linear response is obtained over standard AChE concentration range from 0.1 to 10 nM. To demonstrate the capability of this new biomonitoring method, AChE solutions dosed with different concentrations of paraoxon were used to validate the new AChE assay method. AChE inhibition in OP dosed solutions was proportional to OP concentration from 0.2 to 50 nM. The new AChE activity assay method for biomonitoring of OP exposure was further validated with in vitro paraoxon-dosed RBC samples. The established electrochemical sensing platform for AChE activity assay not only avoids the problem of overlapping substrate specificity with esterases by using selective antibody, but also eliminates potential interference from other electroactive species in biological samples. It offers a new approach for sensitive, selective, and rapid AChE activity assay for biomonitoring of exposure to OPs.