Engineered hybrid carriers with dual stimuli-responsiveness for targeted and sustained prochloraz delivery against gray mold

Traditional pesticide formulations often suffer from limitations such as poor foliar retention, uneven distribution, low plant uptake, and inefficient utilization, necessitating the need for advanced, sustainable alternatives. In this study, a hybrid carrier system, Pec@Pro@Ti-MOF@DE, was developed to enhance the efficiency of prochloraz (Pro) against gray mold ( Botrytis cinerea ). The system integrates titanium metal-organic frameworks (Ti-MOF) anchored onto diatomaceous earth (DE), with pectin (Pec) coating serving as a responsive release barrier. The incorporation of DE significantly improved the foliar adhesion of MOF particles, enabling pesticide presence at infection sites and promoting efficient penetration and systemic translocation. The high surface area of Ti-MOF@DE (731 m 2 /g) facilitated a substantial prochloraz loading capacity of 56.5 %. The pectin coating on the Pro@Ti-MOF@DE functioned as a biological gatekeeper, releasing prochloraz in response to enzymatic pectinase activity and pH changes associated with B. cinerea infection, achieving a 91.5 % cumulative release. Foliar adhesion studies confirmed strong carrier attachment, while fluorescence microscopy revealed bidirectional translocation within plant tissues. In vitro assays demonstrated superior antifungal activity, with an EC 50 of 0.017 µg/mL, significantly lower than that of free prochloraz (0.027 µg/mL). In vivo and post-harvest evaluations further validated the system’s performance, achieving fungal control efficacy of 97.3 % in tomato leaves and 95.6 % in fruits. Therefore, Pec@Pro@Ti-MOF@DE could be used as a biocompatible carrier for site-specific pesticide delivery without compromising plant safety, which would be a sustainable approach to improve prochloraz efficacy while reducing environmental risks in modern agriculture.