Chinese Scientists Develop New Nanoparticles to Improve Pesticide Performance
Hefei, China (ANTARA) — Scientists from the Hefei Institutes of Physical Science, under the Chinese Academy of Sciences, have proposed a new solution to a problem that often troubles agriculture: pesticides washing off plant leaves before they can do their job.
The solution is presented in a study published in the Journal of Controlled Release and was inspired by tiny hair-like structures that help bacteria attach to the human intestine.
Imitating this natural adhesion mechanism, the research team created rough-surfaced silica nanoparticles that cling to leaf surfaces far better than conventional formulations. The technology could reduce pesticide waste and the need for repeated spraying.
According to the researchers, conventional pesticide spraying is highly inefficient. Leaves are coated with a waxy, water-repellent layer, causing spray droplets to bounce off. Rain washes away pesticide residue that has managed to adhere, while sunlight and evaporation break down its active ingredients.
Previous studies have indicated that as much as 90 per cent of pesticides may never reach their intended target, forcing farmers to spray repeatedly. This raises costs and worsens pollution and ecological damage.
The research team looked to bacteria for an answer. Some intestinal bacteria have tiny hair-like structures called pili, which act like small hooks. These structures grip surfaces and prevent the bacteria from being swept away.
The researchers replicated this mechanism by creating minute, hollow silica particles and covering their surfaces with tiny spikes. They then filled the particles with imidacloprid, a commonly used insecticide.
Detailed analysis confirmed that, when sprayed on leaves, the spiky nanoparticles worked like bacterial pili. They lodged in the waxy leaf surface and held fast, like tiny anchors. The particles also formed hydrogen bonds — weak chemical interactions that act like tiny magnets — further strengthening their grip.
“This double grip helps the pesticide remain attached, even in the rain. The carrier also releases the pesticide slowly and resists damage from ultraviolet (UV) light, making it more efficient,” said Wang Guozhong, a researcher at the institute.
The team tested the new formulation on cotton, soybean and tomato leaves. After simulated rainfall, the amount of pesticide remaining on the leaves was more than 4.8 times higher than with a commercial imidacloprid product.
“Safety tests on plants and zebrafish showed no clear signs of harm, indicating that this new pesticide is environmentally friendly and could help pave the way for low-dose, high-efficiency, environmentally friendly pesticide products,” Wang added.