A pH-responsive, kojic acid-based amphiphilic polymer as a nanocarrier for targeted herbicide delivery

Hydrophobic herbicides often suffer from poor solubility and low bioavailability in crop protection applications, which hinders the sufficient uptake of active ingredients by target weeds and severely limits their effectiveness in safeguarding crop growth. To enhance the delivery efficiency and targeting capability of such herbicides, this study developed a pH-responsive amphiphilic polymer nanocarrier using the natural product kojic acid and triethylene glycol divinyl ether as raw materials for loading diuron. This carrier can self-assemble in aqueous media to form stable core-shell nanoparticles with a critical micelle concentration of 6.92 × 10 −3  mg/mL and an average particle size of 181.4 nm after drug loading. In a simulated acidic rhizosphere environment of Echinochloa crus-galli , the drug-loaded nanoparticles exhibited distinct pH-responsive release behavior while maintaining good physical stability. Biological experiments further confirmed that this delivery system significantly enhances the herbicidal activity of diuron against Echinochloa crus-galli , providing new insights and a material foundation for the development of efficient and intelligent herbicide delivery systems.