A core-satellite MOF-on-MOF hybrid for intelligent delivery of multi-agrochemicals for sustainable agriculture

Intelligent delivery formulations of agrochemicals have had a great impact on improving utilization efficiency, reducing chemical usage and easing the risk on the environment. However, constructing smart carriers for multi-agrochemicals to simultaneously control multiple botanic diseases, remains a challenge. In this study, a core-satellite MOF-on-MOF hybrid was designed for intelligent pest and fungus management. Zirconium-based met-al-organic framework (UIO) nanoparticles were synthesized as metal-organic framework (MOF) cores to load the insecticide dinotefuran (DNF). Subsequently, a fungicide tebuconazole (Teb) loaded zeolitic imidazolate framework (ZIF) was formed in situ as MOF satellites. The loading contents of DNF and Teb were 6.87% and 8.59%, respectively. DNF released rapidly under alkaline conditions corresponding to the microenvironment of pests, whereas Teb released preferentially under acidic environment. The EC95 of the MOF-on-MOF hybrid against Exserohilum turcicum was 3.5 times lower than that of Teb alone. After 48 h, the mortality of armyworm treated with 3.0 mg/L MOF-on-MOF hybrid was 87%. The UV resistances of DNF and Teb were 7.0 and 1.9 times higher, respectively, than that of the free pesticides. This work provides a facile technology for precise delivery of multi-agrochemicals, holding substantial promise for sustainable agriculture.