Co-assembly of nanopesticides of abamectin B1a and imidacloprid against Ditylenchus destructor

Abstract

Multi-component active ingredient delivery systems based on co-assembly have the merits of reducing drug dosage, attenuating pest resistance, enhancing ingredient utilization, broadening the control range, etc. and present excellent application prospects. Herein, a carrier-free co-assembled nanopesticide based on two first-line pesticides, abamectin B1a and imidacloprid, is successfully fabricated by a straightforward nanoprecipitation technique alone. NMR, UV-vis titration and molecular dynamics simulations reveal that intermolecular hydrogen bonding and van der Waals forces are the key driving forces for their binding. Less frequently encountered π-alkyl forces also prevail in the co-assembled systems. The co-assembled nanopesticide presents a structured spherical shape with a size of ∼200 nm. Soil permeability and UV degradation resistance are significantly higher than those of the two pure components. The surface of Ditylenchus destructor Thorne (D. destructor) treated with the nanoparticles becomes smooth, and the roughness is significantly lower than that of the control group. The activity of acetylcholinesterase (AchE) in vivo is significantly lower than that in the treatment group alone. AVM@IMI is also shown to have a better biosafety profile than commercial preparations. This strategy is expected to achieve efficient control of D. destructor and allow the green and sustainable development of agricultural controls.