Engineering Porous Nano-Organic Silicon for Enhanced Pesticide Performance in Drone Spraying

A novel porous nano-organic silicon (PNOS) polymer was synthesized through a strategy involving template-assisted polymerization and diluted acid etching by employing nano-CuO as a hard template. The porous polymer particles ranged from 50 to 150 nm and exhibited a high BET surface of 426.0 m2/g. Based on hydrogen-bond-supported pore adsorption confirmed by XPS analysis and molecular docking, the PNOS demonstrated 31.5% loading capacity for toosendanin (TSN). Additionally, nanoencapsulation significantly extended the duration efficacy and photostability of TSN, with the half-life of TSN increased from 2.7 to 8.6 days. After encapsulation under optimized conditions, suitable adjuvants were screened to develop a TSN nanosuspension, which exhibited desirable suspension rate, storage stability, and wetting performance. Furthermore, the nanosuspension was proved to be suitable for aerial application, with high droplet density and coverage in the crop canopy when sprayed by drones. Toxicity assays revealed that the LC50 values of the TSN nanosuspension against Sitobion avenae and Aphis citricola were significantly lower than those of the TSN emulsifiable concentrate. Field efficacy assays through aerial spraying demonstrated that the TSN nanosuspension provided desirable control efficacy and long persistence against both aphid species. The novel PNOS had promising application potential for sustainable aerial crop protection.