High deposition and precise stimulus-response release performance of lignin-coated dendritic mesoporous organosilica nanoparticles for efficient pesticide utilization

The inefficient and improper use of conventional pesticides has prompted the development of targeted and costeffective pesticide delivery systems, which aim to optimize the efficient utilization of pesticides while minimizing environmental pollution in surrounding areas. In this paper, a dual-stimuli-responsive pesticide slow-release nanopesticide system (NES@DMONs@LGN) was designed in this study, utilizing mesoporous silica (DMONs) as a nanocarrier and lignin (LGN) as a capping agent to encapsulate the pesticide molecules within DMONs. This system enables intelligent release of pesticide molecules while preventing environmental pollution caused by leakage. Additionally, NES@DMONs@LGN exhibit excellent specific loading efficiency. The abundant hydrophilic functional groups in the lignin layer on the surface of NES@DMONs@LGN can establish hydrogen bonds with advanced fatty acids and fatty alcohols present in the waxy epidermis of plants, thereby significantly enhancing carrier wettability and adhesion. Typically, phytophagous lepidopteran pests have an alkaline midgut and possess lignin-degrading enzymes. The NES@DMONs@LGN developed in this study are capable of rapid release under high temperature and alkaline conditions. Therefore, the precise release of pesticide molecules in the target pests can be achieved, thus increasing the actual utilization rate of pesticides. The experimental results demonstrated that NES@DMONs@LGN effectively prevented photodegradation of the active ingredient after 48 h of UV irradiation, resulting in a 3.7-fold improvement in photostability and providing robust UV protection. By encapsulating pesticide molecules with nanocarriers, the release of pesticides in non-targeted environments can be prevented, thereby significantly reducing toxicity to zebrafish. Thus, this study provides a promising solution for sustainable greening of agriculture.