Chen Chunyang, Bie Hongke, Duan Jianhang, Li Zhongjie, Dou Yuemao, Wang Huili, Liu Wei, Wang Xuedong
Jiangsu Key Laboratory of Environmental Science and Engineering, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, P. R. China.
Frontiers Science Center for Rare Isotope, School of Nuclear Science and Technology, Institute of National Nuclear Industry, Lanzhou University, Lanzhou 730000, P. R. China.
Environ Sci Technol. 2024 Dec 3;58(48):21339-21349. doi: 10.1021/acs.est.4c07422. Epub 2024 Nov 21.
Herein, we pioneered an innovative methodology for the rapid identification and quantitation of methyl parathion (MP) residues, overcoming the drawbacks of existing methods such as poor selectivity, high costs, and intricate operational procedures. A dual-emitting fluoroprobe SiONPs-Eu was engineered based on silica oxide nanoparticles (SiONPs) conjugated with Eu, and the synthetic conditions were meticulously optimized to ensure exceptional sensitivity and selectivity to 4-nitrophenol (4-NP), one of the MP hydrolytic products. Upon excitation at 317 nm, the blue fluorescence of SiONPs at 400 nm was quenched, while the red fluorescence of Eu at 616 nm remained nearly unchanged, constituting a ratiometric fluorescent change that significantly enhanced the detection stability. The fluoroprobe rapidly detected 4-NP at concentrations below 80 μM within 10 s and gave a limit of detection (LOD) as low as 0.16 μM, markedly lower than the allowable residue limit of MP in China food safety standards. Also, it exhibited excellent anti-interference properties in complex matrices, remaining unaffected by common amino acids, cations, and pesticides. The underlying mechanism of the fluoroprobe was elucidated through time-dependent density functional theory (TD-DFT) calculations. Under optimized hydrolysis conditions, the detection of MP in real rice samples was successfully achieved. Furthermore, the self-developed and dual-channel portable device was conducive to on-site fluorescence detection of 4-NP, offering enhanced stability in contrast to traditional photography-based methods.
在此，我们开创了一种用于快速鉴定和定量甲基对硫磷（MP）残留的创新方法，克服了现有方法选择性差、成本高和操作程序复杂等缺点。基于与铕（Eu）共轭的氧化硅纳米颗粒（SiONPs）设计了一种双发射荧光探针SiONPs-Eu，并对合成条件进行了精心优化，以确保对MP水解产物之一4-硝基苯酚（4-NP）具有出色的灵敏度和选择性。在317 nm激发下，SiONPs在400 nm处的蓝色荧光猝灭，而Eu在616 nm处的红色荧光几乎保持不变，构成了比率荧光变化，显著提高了检测稳定性。该荧光探针在10 s内快速检测出浓度低于80 μM的4-NP，检测限（LOD）低至0.16 μM，明显低于中国食品安全标准中MP的允许残留限量。此外，它在复杂基质中表现出优异的抗干扰性能，不受常见氨基酸、阳离子和农药的影响。通过含时密度泛函理论（TD-DFT）计算阐明了荧光探针的潜在机制。在优化的水解条件下，成功实现了对实际大米样品中MP的检测。此外，自行研制的双通道便携式设备有利于对4-NP进行现场荧光检测，与传统的基于摄影的方法相比，具有更高的稳定性。
