Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100037, P. R. China and State Key Laboratory of Food Nutrition and Safety, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China.
Anal Methods. 2021 May 6;13(17):2005-2010. doi: 10.1039/d1ay00345c.
Organophosphorus pesticides (OPs) residues have caused great concern as they cause great harm to public health. Herein, a ratiometric fluorescent sensing system was developed for the OPs detection with the merits of enzyme-free, simple operation, short-time and sensitivity. The change in the fluorescence signal in the sensing system was provided by guanine-rich DNA (G-DNA) and silver nanoparticles (AgNPs) with terbium ion (Tb3+) and dured. Tb3+ coordinated with the G-DNA to form a DNA-Tb complex to emit green fluorescence, which can be significantly enhanced by AgNPs based on the mechanism of metal enhanced fluorescence. Dured embedded into the G-DNA emits red fluorescence as the built-in fluorescence signal. After adding OPs into the DNA-Tb-dured-AgNPs sensing system, the fluorescence of Tb3+ quenched, while the fluorescence of dured remained unchanged. The OPs detection is implemented enzyme-free or label-free and has the advantage of high sensitivity and reliability. The limit of detection reaches as low as 0.034 μg L-1, and good recoveries are obtained for the OPs detection in tap water and apple. Moreover, the developed sensing system is simple in preparation and low cost, exhibiting an efficient platform to meet the requirement for in situ application in food safety and environmental monitoring.
有机磷农药（OPs）残留引起了极大的关注，因为它们对公众健康造成了极大的危害。在此，开发了一种比率荧光传感系统，用于 OPs 的检测，具有无需酶、操作简单、耗时短和灵敏度高的优点。传感系统中荧光信号的变化由富含鸟嘌呤的 DNA（G-DNA）和银纳米粒子（AgNPs）提供，其中铽离子（Tb3+）和二氮杂菲（dured）。Tb3+与 G-DNA 配位形成 DNA-Tb 配合物发出绿色荧光，AgNPs 基于金属增强荧光的机制可显著增强其荧光强度。嵌入 G-DNA 中的二氮杂菲作为内置荧光信号发出红色荧光。将 OPs 添加到 DNA-Tb-dured-AgNPs 传感系统后，Tb3+的荧光被猝灭，而二氮杂菲的荧光保持不变。该 OPs 的检测无需酶或标记，具有高灵敏度和可靠性的优点。检测的检出限低至 0.034μg/L，在自来水中和苹果中检测 OPs 时得到了良好的回收率。此外，所开发的传感系统制备简单，成本低，为食品安全和环境监测的现场应用提供了一个高效的平台。
