Improving the efficiency and environmental safety of emamectin benzoate through a pH-responsive metal–organic framework microencapsulation strategy

• Published in: Journal of hazardous materials 2024-08, Vol.475, p.134847, Article 134847
• Main Authors: Wei, Zheng, Zhu, Jingxuan, He, Ying, Lai, Jie, Pan, Bingjie, Feng, Kaiyang, Chen, Lihan, Cao, Lidong, Wang, Yan, Qian, Kun
• Format: Article
• Language: English
• Subjects: Bioassay; Emamectin benzoate; Nanocontrolled-release formulation; PCN-222; Safety
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.134847

Herein, we developed a technique for loading nanopesticides onto Metal-Organic Frameworks (MOFs) to control Spodoptera litura. The average short-axis length of the synthesized carrier emamectin benzoate@PCN-222 @hyaluronic acid (EB@PCN-222 @HA) was ∼40 nm, with an average long-axis length of ∼80 nm. This enabled the manipulation of its size, contact angle, and surface tension on the surface of leaves. Pesticide-loading capacity, determined via thermogravimetric analysis, was measured at ∼16 %. To ensure accurate pesticide release in the alkaline intestine of Spodoptera litura, EB@PCN-222 @HA was engineered to decompose under alkaline conditions. In addition, the carrier delayed the degradation rate of EB, enhancing EB’s stability. Loading Nile red onto PCN-222 @HA revealed potential entry into the insect body through feeding, which was supported by bioassay experiments. Results demonstrated the sustained-release performance of EB@PCN-222 @HA, extending its effective duration. The impact of different carrier concentrations on root length, stem length, fresh weight, and germination rate of pakchoi and tomato were assessed. Promisingly, the carrier exhibited a growth-promoting effect on the fresh weight of both the crops. Furthermore, cytotoxicity experiments confirmed its safety for humans. In cytotoxicity assays, PCN-222 @HA showed minimal toxicity at concentrations up to 100 mg/L, with cell survival rates above 80 %. Notably, the EB@PCN-222 @HA complex demonstrated reduced cytotoxicity compared to EB alone, supporting its safety for human applications. This study presents a safe and effective approach for pest control using controlled-release pesticides with extended effective durations. [Display omitted] •A Weak Alkalinity-Directed EB@PCN-222 @HA was engineered for enhanced stability and prolonged effectiveness.•EB@PCN-222 @HA mitigated the degradation of EB and demonstrated superior insecticidal efficacy compared to the EB solution.•EB@PCN-222 @HA showed reduced toxicity towards non-target organisms and L02 cells.•By carrying fluorescent dyes, PCN-222 @HA was able to penetrate the insect body.