Uptake, distribution and translocation of imidacloprid-loaded fluorescence double hollow shell mesoporous silica nanoparticles and metabolism of imidacloprid in pakchoi

• DOI: 10.1016/j.scitotenv.2021.147578
• Publication Date: 2021-05-06T19:08:32Z
• Authors: Meiqing Zhu; Xu Ou; Jun Tang; Taozhong Shi; Xin Ma; Yi Wang; Xiangwei Wu; Qing X. Li; Rimao Hua
• Keywords: 01 natural sciences; 0105 earth and related environmental sciences

Abstract 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.