Metolachlor metal-organic framework nanoparticles for reducing leaching, ecotoxicity and improving bioactivity

Area of Science:

• Materials Science
• Environmental Science
• Agricultural Chemistry

Background:

• Pesticide use, particularly amide herbicides, poses ecological and public health risks due to environmental leaching.
• Metolachlor (METO), a common amide herbicide, faces application limitations because of its tendency to leach.
• Developing controlled-release systems is crucial for mitigating pesticide pollution and improving agricultural practices.

Purpose of the Study:

• To fabricate a novel nanocarrier system for metolachlor (METO) using zeolitic imidazolate framework-8 (ZIF-8).
• To enhance the efficacy and environmental safety of leachable amide herbicides through controlled release technology.
• To investigate the physicochemical properties and performance of the METO-loaded ZIF-8 nanoparticles (METO@ZIF-8).

Main Methods:

• Optimized synthesis parameters for METO@ZIF-8 nanoparticles using response surface methodology (central composite design).
• Characterized nanoparticle size, morphology, surface area, and water dispersibility.
• Evaluated pH-responsive release, soil adsorption, leaching reduction, herbicidal efficacy, phytotoxicity, and ecotoxicity in zebrafish.

Main Results:

• Synthesized uniform dodecahedron METO@ZIF-8 nanoparticles (approx. 54.3 nm) with high surface area and good dispersibility.
• Achieved pH-responsive release, significantly improved soil adsorption, and reduced METO leaching by 10.3–21.7%.
• Demonstrated superior weed control (16.6–48.4% higher than controls), reduced corn phytotoxicity, and lower zebrafish toxicity compared to conventional METO formulations.

Conclusions:

• The METO@ZIF-8 nanocarrier effectively improves amide herbicide efficacy and environmental safety.
• This controlled-release system offers a promising approach to mitigate the adverse effects of leachable pesticides.
• The developed nanocarrier technology contributes to sustainable agriculture and reduced environmental contamination.