State Key Laboratory on Integrated Optoelectronics, Jilin Key Laboratory on Advanced Gas Sensor, College of Electronic Science and Engineering , Jilin University , Changchun 130012 , People's Republic of China.
School of Mechanical and Materials Engineering , Washington State University , Pullman , Washington 99164 , United States.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27605-27614. doi: 10.1021/acsami.9b09849. Epub 2019 Jul 22.
Precise on-site profiling of organophosphate pesticides (OPs) is of significant importance for monitoring pollution and estimating poisoning. Herein, we designed a simple and convenient portable kit based on Ag-responsive hydrogels for accurate detection of OPs. The newly developed hydrogels employed -phenylenediamine (OPD) and silicon quantum dots (SiQDs) as indicator, which possessed ratiometric response. In this sensor, OPs as inhibitor of acetylcholinesterase prevented the generation of thiocholine, which blocked the formation of metal-polymer with Ag, further triggered the oxidation of OPD to yield yellow 2,3-diaminophenazine (DAP) with fluorescence emission at 557 nm. The fluorescence intensity of SiQDs (444 nm) was quenched by DAP through inner filter effect (IFE) process, emerging a typical ratiometric response. Interestingly, the ratiometric signal of kit, which was recorded by smartphone's camera, can be transduced by ImageJ software into the hue parameter that was linearly proportional to the concentration of OPs. The simplicity of portable kit combined with smartphone operation, which possessed high sensitivity (detection limit <10 ng mL) and rapid sample-to-answer detection time (45 min) in agricultural sample, indicating that the methodology offered a new sight for portable monitoring of food safety and human health.
准确的现场分析有机磷农药 (OPs) 对于监测污染和估计中毒情况非常重要。在此，我们设计了一种基于 Ag 响应水凝胶的简单便捷的便携式试剂盒，用于准确检测 OPs。新开发的水凝胶采用邻苯二胺 (OPD) 和硅量子点 (SiQDs) 作为指示剂，具有比率响应。在该传感器中，OPs 作为乙酰胆碱酯酶的抑制剂，阻止了硫代胆碱的生成，从而阻止了 Ag 与聚合物的形成，进一步引发了 OPD 的氧化，生成荧光发射波长为 557nm 的黄色 2,3-二氨基吩嗪 (DAP)。DAP 通过内滤效应 (IFE) 过程猝灭了 SiQDs (444nm) 的荧光强度，产生了典型的比率响应。有趣的是，通过智能手机的摄像头记录的试剂盒的比率信号可以通过 ImageJ 软件转换成色调参数，该参数与 OPs 的浓度呈线性比例。便携式试剂盒与智能手机操作相结合，具有高灵敏度（检测限 <10ng mL）和快速的样本到答案检测时间（45 分钟），这表明该方法为食品安全和人类健康的便携式监测提供了新的思路。
