Preparation and properties of tannic acid coated abamectin/mesoporous silica nano-pesticide delivery system

It is important to increase the retention time of pesticides on the leaf surface of target crops for improving pesticide utilization and reducing the impact of pesticides on the environment. In this paper, we used abamectin (Aba) as a model pesticide and mesoporous silica nanoparticles coated with tannic acid (TA) as a carrier material to construct a nano-pesticide delivery system. Based on the structural and morphological characterization of the nano-pesticide delivery system, we investigated the release performance and foliar adhesion of the nano-pesticide delivery system through simulated release experiments, comparison of contact angle and retention amount on plant foliage and UV photolysis resistance experiments. It is found that tannic acid-coated abamectin-loaded mesoporous silica nanospheres (Aba/MSNs@TA) significantly improve drug wettability on the foliage of Epipremnum aureum, corn and masson pine, and foliar retention is also improved compared to Aba/MSNs. Aba/MSNs@TA exhibits significant pH-responsive release performance, with lower pH environments accelerating the release rate of Aba. In addition, the coating of tannic acid further improves the UV photolytic resistance of the drug in the drug-loaded system.