Smart stimuli-responsive, anti-ultraviolet, and foliar retention rotenone nanocapsules via FeIII-tannic acid in situ coordination assembly for improved wheat aphid control

BACKGROUND Pesticides in agriculture have played an important role and are irreplaceable in increasing the yield of crops and agricultural products. However, ultraviolet photodegradation is a crucial factor that leads to the inefficient usage of most traditional pesticides under sunlight. Rotenone (Rot), as a plant-derived insecticide, is easily degraded under ultraviolet light with loss of biological activity, which severely limits its wide application in the fields. It is therefore necessary to create new formulations to prevent the photodegradation of Rot under ultraviolet radiation. RESULTS Simple, intelligent, and degradable Rot@Fe III -tannic acid (Rot@Fe III -TA) nanocapsules were constructed using a general strategy, where Rot was coated in the core and Fe III -TA networks as the shell prepared via in situ coordination assembly on the interface of oil/water microemulsions. The prepared nanocapsules showed multidimensional stimuli-responsive controlled release performance, containing acidic/alkaline pH, glutathione, H 2 O 2 , and phosphate, which were closely relevant to the physiological environments of crops, and the Fe III -TA shell was finally disassembled in crops against bioaccumulation. Furthermore, the prepared nanocapsules showed remarkable rain washing and UV photolysis resistance on wheat leaf surface for availably wheat aphid control compared with that of technical Rot. In addition, the prepared nanocapsules appeared good safety on seed germination and seedling emergence, and were beneficial for the growth of wheat seedlings. CONCLUSION The prepared Rot@Fe III -TA nanocapsules could effectively prevent the photodegradation of Rot under ultraviolet radiation for wheat aphid control, which has potential application for Rot formulation exploitation in the field in the future. © 2025 Society of Chemical Industry.