Novel Pesticide Carrier with Bionic Stomata-Lotus Pod Structure for Pesticide Hierarchical Storage-Transport and Dynamic Controlled Release

To address the challenge of coordinating "rapid response-sustained protection" in controlled pesticide delivery, this study drew biomimetic inspiration from the multichambered storage structure of lotus seed pods, designing a modified diatom biosilicon-abamectin benzoate/sodium alginate (DA-EB/SA-Ca2+) composite carrier. The carrier features a hierarchical "external response-internal storage" architecture and achieves coordinated drug release through a plant-stomata-like environmental-responsive opening-closing mechanism. This innovative structure presents 56.36% of high loading capacity and the novel controlled-release mode combining "passive diffusion" and "active release". 41.06% of the drug passively diffused in the first stage (within 48 h) to quickly achieve an effective insecticidal concentration. Subsequently, the active release of pesticides is triggered by environmental factors and the release rate and insecticide rate at pH = 5.3 over 72 h were 5.2 and 1.6 times higher than those at pH = 8. Furthermore, a mathematical model of pesticide releases was established to accurately predict soil release behavior from indoor releases (tsoil = 0.08979(8.6705tindoor1/2 - 13.5376)2.0483).