Composite pesticide nanocarriers involving functionalized boron nitride nanoplatelets for pH-responsive release and enhanced UV stability

With increasing global food demand, the production and protection of agricultural crops in safe and secure fashion has become a critical issue. Herein, we report a novel type of nanopesticide based on avermectin (AVM) and composite nanocarriers made from the functionalization boron nitride nanoplatelets (BNNP) with 3-mercaptopropyl trimethoxysilane (MPTMS) and poly(ethylene glycol) diacrylate (PEG). Such nanocarriers exhibit a high pesticide loading capacity (181.9 ± 5.2 mg/g) due to their layered nanostructure and their favorable interactions with AVM molecules achieved through hydrophobic effect, π-π stacking, and electrostatic interactions. By changing pH from 7 to 11, the release kinetics could be transformed to a zero-order process from a first-order process, with about a two-to-three-fold increase in the release rate. The pH-responsive behavior was ascribed to hydrolysis of ester groups of PEG under alkaline conditions. These pesticide nanocarriers reduced the degradation rate of AVM against UV irradiation about 30%. In summary, novel nanopesticides based on BN composite nanocarriers opens new avenues for the delivery of hydrophobic pesticides in the field of agriculture and crop protection.