中文摘要：本文采用扫描电子显微镜（SEM）研究两种不同大小银电极的表面结构以及纳米银电极与壳聚糖层交界面特征，采用循环电流法检测银/壳聚糖电极对胆碱有无的不同反应以及壳聚糖层的绝缘性能，采用安倍法检测电极对有机磷农药酶触反应的产物——胆碱的反应，众多纳米材料中只有银在低电压下不需要做任何改进即可用于胆碱（TCH）检测。结果显示，纳米电极比常用的银电极效果更优：最优条件下对氧磷的检测限为4ppb。采用1%的壳聚糖溶液作为纳米电极与乙酰胆碱酯酶的绝缘液，使得在室温条件下即可制备电极。与传统的有机绝缘油墨不同，壳聚糖溶液具有安全和环境友好的特性。本文还以韭菜和白菜为实验样本，来评估纳米/乙酰胆碱酯酶/壳聚糖电极对有机磷农药残留检测效果。结果显示，标准加标水平下的回收率分别为105.11%和96.41%。纳米银所具有的抗菌性能和壳聚糖所具有的生物适应性、安全可降解性能，保证了纳米/乙酰胆碱酯酶/壳聚糖电极的安全、温和、环境友好等特性，因此本方法具有有机磷农药残留检测的巨大潜力。
外文摘要：A nano-silver electrode immobilizing acetylcholinesterase (AChE) for the detection of organophosphorus (OPPs) pesticides is reported. Scanning electron microscopy (SEM) was used to characterize the surface structure of two kinds of electrodes fabricated with different sizes of silver powders and the interface between chitosan layer and nano-silver powder layer. Cyclic voltammetry was carried out to characterize the response of silver/chitosan electrode in the absence and in the presence of thiocholine (TCh). It was also used to evaluate the insulativity of the chitosan layer. An amperometric method was performed to measure the response of the electrode to TCh, which is the product of the enzymatic reaction for detecting organophosphorus pesticides indirectly. Although there are many kinds of nanoparticles, silver was chosen for its internal advantage in detecting TCh at low potential without further modification. The result shows nano-silver powder has better performance than usual silver powder, and the limit of detection of paraoxon is 4 ppb under optimized conditions. One percent (w/v) chitosan solution was used as binder for the immobilization of nano-silver powder and AChE, which made it possible for independent electrode fabrication at room temperature, whereas 3% (w/v) chitosan solution was used as insulating compound for controlling the electrode area. Unlike traditional organic insulating ink, chitosan is safe and environmentally friendly, and it is used as insulating material for the first time. The flexible nano-silver/AChE/chitosan electrode was evaluated in Chinese chives and cabbage, and the recoveries of standard addition were 105.11 and 96.41%, respectively. Owing to the antibacterial property of nano-silver and the biocompatibility, safety, and biodegradability of chitosan, the proposed method is safe, facile, environmentally friendly, and has great potential in organophosphorus pesticide detection for food safety.
外文关键词：Nano-silver, Chitosan, Electrochemistry, Acetylcholinesterase, Organophosphorus pesticide
作者：Zheng, Qiqi; Yu, Yonghua; Fan, Kai; Ji, Feng; Wu, Jian; Ying, Yibin
作者单位：Zhejiang Univ, Key Lab Equipment & Informatizat Environm Control, Minist Agr, Hangzhou 310058, Zhejiang, Peoples R China.
期刊名称：analytical and bioanalytical chemistry
期刊影响因子：3.125
出版年份：2016
出版刊次：8
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