Nano-biointerface interlocking strategy based on bacteriomorphic silica nanocarriers for high-performance foliar...

Conventional pesticide application suffers from low utilization efficiency due to droplet rebound and rain wash-off. Inspired by gut-colonizing bacteria's adhesion, pilus-like spherical rough hollow silica (SRHS) and rod-shaped rough hollow silica (RRHS) were engineered to improve imidacloprid delivery via leaf-surface mechanical interlocking. Using imidacloprid as active ingredient and sucrose both as an adhesion enhancer, SRHS- and RRHS-based nanopesticides (SRHSIS/RRHSIS) were fabricated via vacuum impregnation. Under simulated rainfall conditions, retention rates were 4.8- and 5.2-fold greater than those of the commercial imidacloprid water-dispersible granule (IMI_WG) reference product. They exhibited uniform dispersion and strong adhesion on the leaves of diverse crops (e.g., cotton, soybean, tomato, eggplant) under lab conditions, demonstrating broad potential applicability in agricultural systems. SRHSIS and RRHSIS showed the highest aphid control efficacy (LC₅₀ = 1.6 mg/L). In planta application at 10 mg/L provided complete protection against aphid (Lipaphis erysimi) infestation on pakchoi. Notably, short-term toxicological tests showed no observable adverse effects on pakchoi and zebrafish following exposure to the nanopesticides. This work provides valuable insights to improve the bioavailability of pesticides, facilitating effective pest control in agricultural production, with potential for extension to other pesticide classes.