Scientists from the Hefei Institutes of Physical Science, Chinese Academy of Sciences, have developed spiky silica nanoparticles that significantly improve pesticide adhesion on crops, addressing a major agricultural challenge where up to 90 percent of conventional sprays wash off or degrade.
In a study published in the Journal of Controlled Release, researchers mimicked gut bacteria pili-hair-like structures that function as hooks-to design hollow, rough-surfaced silica nanoparticles loaded with imidacloprid, a common insecticide.
When sprayed on waxy leaf surfaces, the spiky particles lock in physically like anchors and form chemical hydrogen bonds. This "double grip" prevents wash-off from rain, resists UV damage, and enables slow release, said researcher Wang Guozhong.
In tests on cotton, soybean, and tomato leaves subjected to simulated rainfall, the new formulation retained over 4.8 times more pesticide than commercial imidacloprid products.
Safety evaluations on plants and zebrafish indicated no clear harm, offering an eco-friendly path toward low-dose, high-efficiency green pesticides.