Downsizing gum Arabic-based abamectin particles using flash nanoprecipitation method for enhanced pesticide deposition

Abstract

Pesticides are vital for ensuring crop protection and stable yields, but their low efficiency and eco-unfriendly carriers raise environmental concerns. In this study, abamectin nanopesticides were designed and fabricated using natural polysaccharides [gum arabic (GA)] and a co-stabiliser via flash nanoprecipitation (FNP) method to reduce the size of nanopesticides and enhance their foliar affinity and deposition. Various co-stabilisers were innovatively introduced into the FNP process; the synergy between GA and the co-stabiliser significantly reduced the particle size (111.5 nm), narrowed the size distribution (polydispersity index = 0.078), and enhanced the stability and release performance of the nanopesticides. Importantly, the downsized nanopesticides effectively improved retention on leaf surfaces, reducing pesticide loss. In addition, because of the excellent control capability of the FNP method, the particle size of the nanopesticides could be flexibly adjusted by modifying the flow-based process parameters. Nanopesticides with small sizes demonstrated good control efficacy against Tetranychus urticae, comparable to those of commercial emulsion in water formulations. This study provides an effective approach for enhancing the utilisation efficiency of pesticide droplets by reducing particle size to ensure sustainable agriculture.