Bioadhesive and pH-Responsive ZnO@Polydopamine Core-Shell Nanocarriers for Intelligent Pesticide Delivery and...

The development of intelligent nanocarriers capable of overcoming the intrinsic limitations of conventional pesticides, including poor foliar adhesion, photodegradation, and nonspecific release, remains a major challenge in agrochemical science. Herein, we report a multifunctional core-shell nanocarrier (Pro@ZnO@PDA, denoted as PZP NPs) constructed via interfacial engineering, in which prochloraz-loaded ZnO nanoparticles (ZnO NPs) are encapsulated within a polydopamine (PDA) shell. The rough surface of the ZnO core enables a high pesticide loading capacity of 12%, while the PDA shell markedly enhances leaf adhesion, reducing the contact angle on plant leaves by 25.4%, thereby improving foliar retention. Benefiting from acid-sensitive interfacial dissociation between the PDA shell and ZnO core, the nanocarrier exhibits pH-responsive release behavior, achieving a targeted prochloraz release of 76% under acidic conditions (pH 5.4). In addition, the ZnO core effectively shields the active ingredient from ultraviolet irradiation, resulting in a 23.3-fold enhancement in photostability, whereas the PDA shell provides efficient photothermal conversion, inducing an elevation of temperature up to 38.8 °C under light exposure. The integration of controlled chemical release and photothermal effects gives rise to a synergistic antifungal mechanism, maintaining an inhibition rate exceeding 60% after 7 days of irradiation. Notably, PZP NPs exhibit bidirectional translocation within plants, addressing the limited systemic transport of conventional fungicides. This work demonstrates an interfacial-engineered, stimulus-responsive nanoplatform that offers a promising strategy for intelligent and efficient pesticide delivery.