Fluorescent labeling techniques have been increasingly used to study the transport of pesticides in crops instead of radioisotope techniques due to the high cost, low resolution and handling and disposal of radioisotope materials. Nevertheless, the use of fluorescent labeling techniques to study the uptake and translocation mechanisms of pesticides in crops has rarely been reported. The distribution, translocation and metabolism of imidacloprid in the vegetable pakchoi were studied via a combination of fluorescence microscopy and UPLC-MS/MS. The translocation rate of imidacloprid-loaded fluorescence double hollow shell mesoporous silica nanoparticles (FL-MSNs@Im) under sunlight conditions were observed by fluorescence microscopy to be higher than that under the dark. The FL-MSNs@Im was mainly transported from the ducts to the stem and leaf parts through transpiration under hydroponic conditions. In contrast, FL-MSNs@Im was transported downward mainly through the sieve tubes of the phloem driven by photosynthesis after the foliar spray. Moreover, fewer metabolites of imidacloprid from FL-MSNs@Im were produced than those from 70% Im granules. This work revealed how FL-MSNs@Im was absorbed, distributed and translocated as well as how the released imidacloprid was metabolized in pakchoi plants.

由于成本高，分辨率低以及放射性同位素材料的处理和处置，荧光标记技术已越来越多地用于研究农作物中农药的运输，而不是放射性同位素技术。然而，很少有人报道使用荧光标记技术来研究农作物中农药的吸收和转运机制。结合荧光显微镜和UPLC-MS / MS研究了吡虫啉在蔬菜小白菜中的分布，易位和代谢。通过荧光显微镜观察到，吡虫啉负载的荧光双空心壳介孔二氧化硅纳米粒子（FL-MSNs @ Im）在阳光条件下的转运速率高于黑暗条件下的转运速率。FL-MSNs @ Im主要是在水培条件下通过蒸腾作用从管道传输到茎和叶的一部分。相反，在叶面喷洒后，FL-MSNs @ Im主要通过光合作用驱动的韧皮部的筛管向下运输。此外，与70％Im颗粒相比，FL-MSNs @ Im产生的吡虫啉代谢产物更少。这项工作揭示了FL-MSNs @ Im如何被吸收，分布和转移，以及释放的吡虫啉如何在小白菜植物中代谢。