Tyrosine-Conjugated Prodrug Self-Assembly for Improvement of Utilization Efficiency and Reduction of Environmental Risks of Carfentrazone

Herbicides, owing to their advantages of convenience, high efficiency, and cost-effectiveness, have become an indispensable tool in modern agricultural production. However, low utilization efficiency caused by the inherent physicochemical limitations of some herbicides leads to potential risks to the environment and human health. Herein, an amphipathic prodrug (CT) was synthesized by conjugating lipophilic carfentrazone (CAR) with hydrophilic tyrosine (TYR) via an esterification reaction and subsequently self-assembled into CT nanoparticles (CT NPs) through multiple noncovalent forces in an aqueous solution. The results showed that the obtained CT NPs, with remarkable stability under various conditions, possessed excellent physicochemical characteristics, including a small particle size (150 nm), low PDI (0.228), positive zeta potential (+8.99 mV), and low surface tension (54.81 mN m –1 ), thereby improving wettability and maximum retention on weed leaves, as well as reducing soil leaching of CAR WDG. Importantly, owing to the introduction of the tyrosine moiety, CT NPs exhibited acropetal and basipetal translocation ability in the plant and superior herbicidal efficacy compared to CAR WDG, while showing good biosafety toward wheat and maize seedlings. Therefore, this study offers a promising strategy for designing herbicide nanoformulations with enhanced efficacy and improved environmental safety.