Recently, scientists from the Chinese Academy of Sciences (CAS) developed a new technology, near infrared light (NIRL)-driven release imidacloprid (NDRI), to improve utilization efficiency with its magnetic collectability property. This research was conducted by a team led by Prof. WU Zhengyan from the Institute of Intelligent Machines of the Hefei Institutes of Physical Science.

Pesticides play an important role in controlling weeds, pests, and diseases in modern agriculture for the promotion of grain yield. However, traditional pesticides tended to enter the atmosphere, water, and soil easily through runoff, volatilization, and leaching, leading to serious environmental issues. Therefore, it's urgent to develop new approaches to control the pesticide loss.

In this research, NDRI, which was constructed by agarose hydrogel (AG), CuS-polydopamine (CP), zeolitic imidazolate framework-8 (ZIF-8), imidacloprid (IM), and ferriferous oxide (Fe₃O₄), displayed a good magnetic collectability property because of the existence of Fe₃O₄.

Besides, it could be reused for at least four times. NDRI ZIF-8 was used to efficiently load IM molecules. CP, a photothermal agent, could soften AG and enlarge the pores in hydrogel spheres under NIRL, resulting in the release of IM.

Thus, NDRI possessed an excellent controlled-release performance under NIRL and owned fine biosafety and stability against coexisting ions and pH.

This study offered a new strategy to control the release of IM, improve utilization efficiency, and decline pesticide usage and contamination to the environment.

This research was supported by the Science and Technology Service Program of CAS, the National Key R&D Program of China, and the Key R&D Program of Ningxia Province.

Schematic illustration of mechanism. (Image by ZHANG Lihong)