基于二氧化锆纳米粒子固定乙酰胆碱酯酶的甲基对硫磷传感器

先在金电极表面电沉积二氧化锆纳米粒子并固定乙酰胆碱酯酶(AChE),将此电极浸入含有不同浓度的有机磷溶液中,根据电极在底物氯化乙酰巯基胆碱中电化学信号强度的大小来实现溶液中有机磷的定量检测.以甲基对硫磷为分析目标物,研究了传感器的主要响应特性、选择性及再生性能,考察了底物浓度、工作电位及溶液pH值对分析性能的影响.结果表明,该有机磷传感器在5.0×10-7～5.0×10-4 g/L浓度范围内对目标分析物有线性响应,检出限为1.0×10-7 g/L.该传感器灵敏度高,非特异性吸附小,再生性好,所用的二氧化锆纳米粒子层制备简单、操作方便,具有较大的应用潜力.

Studies on a Novel parathion-methyl Biosensor Design Based on Acetylcholinesterase Immobilized by Zirconia Nanoparticle

In this paper, a novel biosensor for detecting organophosphorus has been prepared. Firstly, a zirconia film is electrodeposition onto the cleaned surface of gold electrode. Then acetylcholinesterase can be immobilized on these zirconia nanoparticles by adsorption. Putting the electrode into organophosphorus solution of different concentrations, we can quantitatively determine the organophosphorus concentration according to the electrochemical response intensity of the modified electrode in the substrate of acetylthiocholine chloride solution. Taking parathion-methyl as example, the effects of substrate concentration, applied potential and solution pH value on the analytical performance have been investigated, and the response character, reproducibility and interferences of the biosensor are also tested. The proposed biosensor in optimal conditions has a linear range of 5.0×10-7~5.0×10-4 g/L for organophosphorus detection, and its detection of limit is 1.0×10-7 g/L. Moreover, the proposed biosensor has advantages in high sensitivity, low non-specific absorption and advantageous regeneration process. The process for preparation of zirconia nanopaticles is simple and convenient. It provides a new method for fabricating other immunosensors.