基于目标物调控原位生成量子点的杀扑磷荧光传感新方法研究  

Target-controlled In-Situ Formation of Quantum Dots for Fluorescence Sensing of Methidathion

作　　者：王雪梅 赵岁欣 李海银[1] 李峰[1] WANG Xue-Mei;ZHAO Sui-Xin;LI Hai-Yin;LI Feng(College of Chemistry and Pharmaceutical Sciences,Qingdao Agricultural University,Qingdao 266109,China)

机构地区：[1]青岛农业大学化学与药学院,青岛266109

出　　处：《分析化学》2022年第3期375-383,共9页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.21775082,22076090)资助。

摘　　要：基于目标物调控原位生成荧光物质,建立了硫化镉量子点(CdS QDs)介导的荧光传感器,实现了大米中有机磷农药杀扑磷的高灵敏、高选择性分析检测。乙酰胆碱酯酶(AChE)催化水解硫代乙酰胆碱(ATCh)生成硫代胆碱(TCh),其作为稳定剂诱导原位生成大量CdS QDs,体系荧光信号增强。当目标农药杀扑磷存在时,AChE活性被抑制,无法有效催化水解ATCh生成TCh,CdS QDs生成量减少,致使检测体系的荧光信号降低。基于目标物加入前后检测体系荧光强度的变化,实现了杀扑磷的高灵敏检测,检出限为0.024 ng/mL(S/N=3)。利用本方法检测大米样品中杀扑磷的含量,加标回收率在96.7%~102.4%之间。本研究为食品中有机磷农药残留的灵敏与精准检测提供了新思路。A highly sensitive and reliable fluorescence sensor for detection of organophosphorus pesticide(OP)based on target-controlled in-situ formation of sadmium sulfide quantum dots(CdS QDs)was developed.Acetylcholinesterase(AChE)catalyzed hydrolysis of acetylthiocholine(ATCh)into thiocholine(TCh),which acted as stabilizing agent to induce the formation of CdS QDs,subsequently improving the emission intensity.Whereas,upon the addition of target methidathion(Met),AChE activity was depressed and thus was not capable of catalyzing hydrolysis of ATCh into TCh.In this context,CdS QDs were not formed and the emission intensity of detection solution was not enhanced,justifying the close relationship between fluorescence signal and Met concentration.Therefore,highly sensitive analysis of Met was achieved on the basis of change in fluorescence emission with a limit of detection of 0.024 ng/mL(S/N=3).Furthermore,the developed fluorescence sensor was successfully employed to detect Met in extract solution of rice with recoveries of 96.7%-102.4%.Overall,the CdS QDs-based sensor presented a new thinking way to highly sensitive and reliable analysis of OPs,favoring OPs-related food safety.

关 键 词：硫化镉量子点 有机磷农药 杀扑磷 乙酰胆碱酯酶 荧光传感器 

分 类 号：O657.3[理学—分析化学] TS207.53[理学—化学]