Fabrication of a nano-herbicide QNC@BA-COF with high control efficiency and reduced side effects

The low efficiency of herbicide formulations poses environmental risks during spraying. Nano-based encapsulation technology can enhance utilization efficiency for sustainable agriculture. Covalent organic frameworks (COFs) serve as potential nanocarriers for pesticide loading, although their poor solubility limits the loading capacity. Herein, the insoluble herbicide quinclorac (QNC) was loaded into a pyrene-based COF (BA-COF) via one-step solvothermal synthesis to fabricate a nanoherbicide formulation (QNC@BA-COF). Molecular dynamics simulations showed that QNC molecules were loaded into the BA-COF via π-π stacking interactions. QNC@BA-COF was 44.7% more effective against barnyard grass ( Echinochloa crus-galli ) than commercial QNC wettable powder (QNC WP) at 100 g ai/hm 2 , with minimal adverse effects on rice ( Oryza sativa ) seedlings and reduced toxicity toward zebrafish ( Danio rerio ), and human cells. Additionally, QNC@BA-COF-treated soil contained more beneficial microbes than those treated with QNC. This study presents a novel method for loading insoluble agrochemicals and a promising nanoherbicide formulation for sustainable agriculture. • A one-step solvothermal method was used to create the nano herbicide QNC@BA-COF. • MD simulations show that QNC is loaded into BA-COF via π-π stacking interactions. • QNC@BA-COF is more effective against barnyard grass than QNC WP. • QNC@BA-COF exhibited lower toxicity to rice seedlings, zebrafish, and human cells. • QNC@BA-COF is eco-friendly and improves beneficial microbes in the soil.