Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
Biosens Bioelectron. 2011 Oct 15;28(1):152-7. doi: 10.1016/j.bios.2011.07.012. Epub 2011 Jul 18.
Here, a simple label-free colorimetric sensing method for organophosphate (OP) nerve agents and pesticide based on catalytic reaction of acetylcholine esterase (AChE) and the aggregation of lipoic acid (LA) capped AuNPs has been established, which is highly sensitive with a limit of detection (LOD) lowered to pM level. In this method, only the AChE hydrolysis product of acetylthiocholine (ATCh), i.e., cationic thiocholine (TCh) can induce the aggregation of LA capped AuNPs along with a distinct color change from red to steel-blue. When OPs as enzyme inhibitors exist, the generation of TCh can be suppressed and the color change of LA capped AuNPs is gradually diminished according to different concentrations of OPs. The feasibility of this method has been demonstrated by sensitive measurement of OP nerve agents and pesticide in a spiked fruit sample with reliable results. This distinct and rapid colorimetric response enables us to readily probe OPs without more technical demand.
本文建立了一种基于乙酰胆碱酯酶（AChE）催化反应和巯基己酸（LA）修饰金纳米粒子（AuNPs）聚集的简单、无需标记的有机磷（OP）类神经毒剂和农药比色传感检测方法，其检测限（LOD）可低至皮摩尔级。在该方法中，只有乙酰硫代胆碱（ATCh）的 AChE 水解产物，即阳离子硫代胆碱（TCh），才能诱导 LA 修饰的 AuNPs 聚集，同时溶液颜色从红色变为钢蓝色。当存在作为酶抑制剂的 OP 时，TCh 的生成会受到抑制，并且 LA 修饰的 AuNPs 的颜色变化会根据 OP 的不同浓度逐渐减弱。该方法已通过在加标水果样品中对 OP 类神经毒剂和农药进行灵敏测量得到验证，结果可靠。这种明显且快速的比色响应使我们能够无需更多技术要求即可轻松探测 OP。
