Bimetallic MOF - Based Hybrid Platform with Dual Stimuli-Responsiveness for Sustained Release and Enhanced Retention

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Pesticide delivery carriers provide protection against pathogens but face significant challenges, including limited loading capacity, rapid release rates, and inconsistent performance. To address these issues, this study develops a dual-stimuli-responsive pesticide delivery carrier, featuring an iron–copper bimetal–organic framework (Fe–Cu MOF) supported on diatomaceous earth (DE) and coated with lauric acid (LA). Here, DE serves as a biocompatible scaffold, enhancing the adhesion and retention of MOF particles at target sites, thereby improving the pesticide localization and delivery efficiency. The carrier exhibits a high thiabendazole (Tbz) loading capacity of 38.14% owing to its nanoporous structure. The LA coating functions as a pH- and temperature-responsive barrier, regulating pesticide release to prolong the treatment duration and minimizing the need for repeated applications. The carrier demonstrates controlled release rates of 80.73% at pH 5 and 96.55% at 40 °C, confirming its dual-stimuli responsiveness. In vitro assays reveal 92.26% inhibition of Botrytis cinerea at 1 μg mL –1, while in vivo experiments on tomato plants and fruits show complete inhibition at 200 μg mL –1 . Additionally, the developed composites adhere strongly to leaves through electrostatic and hydrogen-bonding interactions, reducing the loss of pesticide due to rain erosion. Overall, DE-MOF-Tbz-LA presents a promising and efficient alternative to conventional pesticide applications.