A multi-stimuli–response metal–organic framework nanopesticide for smart weed control in agriculture†

Abstract

Herbicides play an important role in weed control when it comes to ensuring a high and consistent yield in agriculture, but their effectiveness is often compromised by climatic variables. Therefore, improving the climatic adaptability of pesticides is crucial to ensure sustainable agricultural development. In this study, a novel bispyribac-sodium (BIS)–zeolitic imidazolate framework-8 (ZIF-8) nanopesticide (BIS@ZIF-8) with excellent multi-stimuli-responsive properties was synthesized. The nanopesticide BIS@ZIF-8 showed a multi-stimuli response and efficient weed control. In addition, the BIS@ZIF-8 nanocomposite showed strong resistance to rainwater erosion on leaf surfaces with a BIS retention rate of 76.26% under simulated rainwater, which was 41.54% higher than the BIS retention rate of the pure herbicide. Under UV light and acidic conditions, a high concentration of BIS was released from the BIS@ZIF-8 nanocomposite, resulting in an improved weed control effect. Further analyses showed that the BIS@ZIF-8 nanocomposite retained its structural stability and adhered to the weed under rainy conditions through electrostatic interaction. Conversely, the BIS@ZIF-8 nanocomposite was depolymerized under UV light irradiation and released BIS to kill weeds. In addition, BIS@ZIF-8 showed excellent herbicidal activity under field conditions with good biosafety. This work provides a new strategy to avoid environmental and climate-induced pesticide losses and paves the way for smart weed control in agriculture.