A Disaggregation Strategy for Nanopesticide Fabrication: Investigating the Impact of Nanosizing on Pesticide Biointeractions

ABSTRACT Clarifying the intrinsic impact of nanosizing on pesticide biointeractions remains challenging because most nanopesticides are formulated with nanocarriers or surfactants that may influence these interactions. Here, we report a disaggregation strategy for fabricating nanopesticides without nanocarriers or surfactants. Adding acetic acid to an emamectin benzoate (EB) suspension yielded a stable EB nanopesticide (HOAc‐EB) with an average particle diameter of 7 nm. In HOAc‐EB, acetic acid disrupted hydrogen bonding in EB rather than forming complexes with it. Nanosizing significantly increased bioactivity against Megalurothrips usitatus and Meloidogyne enterolobii , improved foliar and root penetration, and reduced soil adsorption. Compared with EB, HOAc‐EB reduced the 24‐h LC ₅₀ by 91% against Megalurothrips usitatus (3.02 to 0.280 mg·L ⁻¹ ) and by 56% against Meloidogyne enterolobii (18.5 to 8.1 mg·L ⁻¹ ), along with 5.1‐fold higher peak foliar penetration in cowpea and 4.4‐fold higher peak root penetration in chili pepper at 1000 mg·L ⁻¹ . Field trials confirmed improved control of Meloidogyne enterolobii . HOAc‐EB was safe for crops at 1000 mg·L ⁻¹ and showed no greater toxicity than EB in zebrafish, earthworms, or mice. This study provides insights into the impact of nanosizing on pesticide biointeractions. The simple, eco‐friendly, and cost‐effective construction approach advances the practical production and agricultural applications of HOAc‐EB.