ZnAg-ZIF@MPN nanoplatform for efficient pesticide delivery with hierarchical encapsulation, pH-responsive release, and enhanced field stability

A ZnAg-ZIF@MPN nanopesticide was constructed via hierarchical MOF loading and metal–phenolic network encapsulation. • Metal node engineering significantly enhanced neonicotinoid pesticide loading capacity within ZIF microporous frameworks. • The MPN shell enabled pH-responsive release behavior and improved environmental stability under light exposure. • The hybrid nanoplatform exhibited enhanced foliar adhesion and rainfall resistance, reducing pesticide loss. • The system achieved improved insecticidal efficacy and lower final residue with favorable crop safety. Zeolitic imidazolate frameworks (ZIFs) emerge as promising pesticide delivery platforms due to their high porosity, structural tunability, and potential for stimuli-responsive release. However, their practical application is still constrained by limited loading capacity, insufficient environmental stability, and poor foliar retention under field conditions. Herein, a hierarchical nanopesticide system (ZnAg-ZIF/NIT@MPN) is constructed through a dual-engineering strategy combining bimetallic framework design and interfacial metal–phenolic network (MPN) coating. The incorporation of Zn 2+ and Ag  +  enables the formation of a stable ZIF matrix with enhanced pesticide loading capacity, which is further improved through parameter optimization. Subsequently, in situ deposition of a tannic acid (TA)-based MPN shell provides an additional functional interface for environmental regulation and delivery control. The resulting nanopesticide exhibits a confinement–interface synergistic mechanism, where the ZIF core ensures efficient pesticide encapsulation and structural stability, while the MPN shell regulates environmental responsiveness and interfacial interactions. This architecture significantly enhances photostability and enables pH-triggered release behavior, achieving rapid pesticide release under acidic conditions following first-order kinetics. In addition, ZnAg-ZIF/NIT@MPN shows improved wettability, foliar adhesion, and rainfastness, thereby reducing pesticide loss under environmental stress. Bioassays demonstrate markedly improved insecticidal efficacy against whiteflies with 95% mortality within 48 h, while maintaining favorable biosafety toward crop germination and early growth. Furthermore, residue analysis indicates reduced pesticide persistence at the harvest stage, while metal-leakage analysis reveals limited release of framework-derived Ag, Zn, and Fe species under the tested conditions. Overall, this work presents a hierarchical nanopesticide design strategy based on core–shell confinement and interfacial regulation synergy, offering a viable approach for improving pesticide efficiency, environmental stability, and agricultural safety in sustainable crop protection systems. Download: Download high-res image (179KB) Download: Download full-size image