Catechol functionalized hat-shape carriers for prolonging pesticide retention and flush resistance on foliage

Retention, a crucial process in pesticide spraying, is closely related to pesticide utilization efficiency and severely impacted by both low surface energy components and micro/nanostructures of foliage. To date, many pesticide carriers have been designed based on either foliar components or structures to enhance pesticide retention. However, as far as we know, there have been no reports taking these two factors into account simultaneously. Herein, we present a novel strategy to address this issue by taking advantage of both non-covalent interactions and topology effect between pesticide carriers and crop leaves. By grafting adhesive catechol-containing polymers onto the surface of hat-shape carriers (HSCs) via a one-step esterification reaction, a series of pesticide-loaded catechol functionalized hat shape carriers (pesticide-loaded Cat-HSCs) with high loading capacity were successfully prepared. Upon spraying on rice and wheat leaves, these functionalized carriers could target both the micropapillae and nanosplinters on foliage driven by the “hanger-hat” topology effect and non-covalent interactions, resulting in great improvement of foliar affinity, pesticide retention, and flush resistance. Moreover, pesticide-loaded Cat-HSCs possess a 15-day sustained-release property and satisfactory efficacy in controlling wheat powdery mildew. Overall, our resource-saving pesticide carrier provides an effective strategy for prolonging pesticide retention and reducing pesticide loss in agro-production.