Cu 2+ -Triggered Carbon Dots with Synchronous Response of Dual Emission for Ultrasensitive Ratiometric Fluorescence Determination of Thiophanate-Methyl Residues

作者：Yong Han, Weixia Yang, Xueli Luo, Xie He, Ying Yu, Chunhua Li, Wenzhi Tang, Tianli Yue, Zhonghong Li · 发表于：Journal of Agricultural and Food Chemistry · 年份：2019 · DOI：10.1021/acs.jafc.9b04720 · 被引用次数：78 · 研究领域：Carbon and Quantum Dots Applications、Sulfur Compounds in Biology、Electrochemical sensors and biosensors

Copper ion (Cu 2+ )-triggered carbon dots (CDs/Cu) with dual emissions were utilized to develop a ratiometric fluorescence sensor for ultrasensitive detection of inert thiophanate-methyl (TM). TM could be recognized by CDs/Cu through π–π stacking and could chelate Cu 2+ of CDs/Cu through metal ion coordination, inducing synchronous fluoresent quenching of the dual emission of CDs/Cu based on the excited state intramolecular proton transfer and the ligand-to-metal charge transfer. The fluorescence ratio of CDs/Cu ( F 416 / F 481 ) linearly responded in a TM concentration of 0.10–20.00 μmol/L with an ultralow limit of detection of 2.90 × 10 –6 μmol/L. A synchronous response of the ratiometric sensor enhanced the specificity toward TM and presented remarkable capability of anti-interference in complex matrices. The sensor exhibited satifactory accuracy and precision for practical applications with recoveries of 88.33–101.09% and relative standard deviations of 1.61–5.06%, demonstrating an ultrasensitive ratiometric fluorescent nanosensor for detecting pesticides residues in complex matrices.