Pathogen-Responsive Release of Copper-Doped ZIF-8 Nanopesticide Carriers for Agricultural Application

The precise targeted release of active chemical pesticide ingredients using nanomaterials is a promising approach to improve the efficacy of chemical pesticide control. Taking tobacco black shank, a common soil rhizosphere disease, as the research object, Phytophthora nicotianae was isolated in the early stage, and transcriptome analysis revealed that Pn releases pectinase when infecting plants. Based on this characteristic, an intelligent, pathogen-responsive, single-atom-doped fungicide-targeted delivery carrier was designed. Pectin-coated copper-doped ZIF-8 was used to load metalaxyl, a commonly used fungicide with good efficacy against Pn. The synthesized pMet@Cu-ZIF-8 carrier has a size of only 44 nm, and the encapsulation efficiency of the active ingredient reached 88.62%. Under the stimulation of the pectinase produced by Pn, the release period was shortened by 3 h, from 7 d. Due to the antimicrobial effect of the copper atom doping, the loaded pMet@Cu-ZIF-8 exhibited a 53% improvement in antimicrobial activity against Pn. Environmental safety tests showed that the cell toxicity and the biological toxicity to model organisms such as zebrafish and bees were at very low levels. The pMet@Cu-ZIF-8 developed in this study for the prevention and control of soil rhizosphere diseases is of great significance for improving efficacy and reducing the usage of chemical pesticides.