HEFEI: Chinese scientists have developed a nanoparticle-based pesticide delivery system that helps insecticides adhere more effectively to crop leaves, potentially reducing chemical waste, repeated spraying and environmental pollution.
Researchers at the Hefei Institutes of Physical Science under the Chinese Academy of Sciences designed the technology by drawing inspiration from bacteria that use tiny hair-like structures to attach themselves to surfaces.
The findings, published in the Journal of Controlled Release, suggest that the new approach could improve pesticide efficiency by preventing chemicals from being easily washed away by rain.
Conventional pesticide spraying often results in substantial chemical losses because plant leaves have waxy, water-repellent surfaces that prevent droplets from adhering properly.
Rainfall can wash away deposited pesticides, while sunlight and evaporation reduce their effectiveness. According to previous studies cited by the researchers, as much as 90 percent of applied pesticides may fail to reach their intended targets.
These losses increase costs for farmers, require repeated spraying and contribute to environmental contamination.
To address the problem, the research team developed hollow silica nanoparticles with rough, spike-covered surfaces that mimic structures known as pili, which help certain bacteria attach to the human intestinal lining.
The scientists loaded the particles with imidacloprid, a commonly used insecticide, to test their effectiveness as a pesticide delivery system.
When applied to leaves, the microscopic spikes anchor the particles to the waxy surface. Additional hydrogen bonds strengthen their attachment, helping the pesticide remain in place under wet conditions.
According to researcher Wang Guozhong, the combination of physical adhesion and chemical bonding improves pesticide retention even during rainfall.
The nanoparticles also release the insecticide gradually and provide protection against ultraviolet radiation, potentially extending its effectiveness.
Tests show stronger pesticide retention after rainfall
The research team tested the formulation on cotton, soybean and tomato leaves to assess its ability to withstand rain.
Following simulated rainfall, pesticide retention was more than 4.8 times higher than that achieved with a commercially available imidacloprid formulation.
The results indicate that the technology could help reduce the amount of pesticide lost during application and improve the efficiency of crop protection.
Researchers also conducted preliminary safety assessments involving plants and zebrafish.
Wang said the tests showed no clear signs of harmful effects under the conditions examined, suggesting potential for developing lower-dose pesticide products with improved environmental performance.
The findings offer a possible approach to making agricultural chemicals more efficient while reducing unnecessary pesticide use.
However, the study’s reported results are based on the tested formulations and conditions, and the technology’s wider agricultural applications would require further evaluation.