Abstract：
BACKGROUND: Conventional pesticide formulations are often inefficient because of low biological uptake after spraying. Controlled release nanopesticides can release pesticides precisely in response to specific stimuli, thereby killing pests and pathogens using the least effective concentration. This study aims to develop nanocapsule-based photo-decomposable nanopesticides for efficient pesticide control.
RESULTS: The target nanopesticides were successfully fabricated using layer-by-layer assembly of the negative azobenzene-grafted hyaluronic acid (azo-HA) and positive polydimethyldiallylammonium chloride (polyDADMAC), confirmed by UV-visible, dynamic light scattering, Zeta potential and transmission electron microscopy measurements. The particle size and Zeta potential of the fabricated nanocapsules were 220 nm and +46.1 mV, respectively, and the nanocapsules were found to remain stable for up to 30 days. The optimized drug loading and encapsulation ratio of imidacloprid (IMI) in IMI/azo-HA@polyDADMAC were 21.5% and 91.3%, respectively. Cumulative release of IMI from the nanopesticides increased from ~50% to ~95% upon UV light irradiation (365 nm). The half lethal concentration (LC50) value of the nanopesticides toward Aphis craccivora Koch decreased from 2.22 to 0.55 mg L-1 upon UV light irradiation.
CONCLUSIONS: The trans to cis transformation of the azo group in HA decomposed IMI/azo-HA@polyDADMAC nanopesticides upon UV irradiation, thus facilitating the release of IMI, resulting in a decrease in the concentration of pesticides required for efficient pesticide control. Our work demonstrated the great potential of light-responsive nanocapsules as a controlled release nanocarrier for efficient and eco-friendly pesticide control in sustainable agriculture. © 2024 Society of Chemical Industry.
RESULTS: The target nanopesticides were successfully fabricated using layer-by-layer assembly of the negative azobenzene-grafted hyaluronic acid (azo-HA) and positive polydimethyldiallylammonium chloride (polyDADMAC), confirmed by UV-visible, dynamic light scattering, Zeta potential and transmission electron microscopy measurements. The particle size and Zeta potential of the fabricated nanocapsules were 220 nm and +46.1 mV, respectively, and the nanocapsules were found to remain stable for up to 30 days. The optimized drug loading and encapsulation ratio of imidacloprid (IMI) in IMI/azo-HA@polyDADMAC were 21.5% and 91.3%, respectively. Cumulative release of IMI from the nanopesticides increased from ~50% to ~95% upon UV light irradiation (365 nm). The half lethal concentration (LC50) value of the nanopesticides toward Aphis craccivora Koch decreased from 2.22 to 0.55 mg L-1 upon UV light irradiation.
CONCLUSIONS: The trans to cis transformation of the azo group in HA decomposed IMI/azo-HA@polyDADMAC nanopesticides upon UV irradiation, thus facilitating the release of IMI, resulting in a decrease in the concentration of pesticides required for efficient pesticide control. Our work demonstrated the great potential of light-responsive nanocapsules as a controlled release nanocarrier for efficient and eco-friendly pesticide control in sustainable agriculture. © 2024 Society of Chemical Industry.
摘要：
背景:由于喷雾后的低生物吸收,常规农药制剂通常是低效的。控释纳米农药可以在特定刺激下精确释放农药，从而使用最不有效的浓度杀死害虫和病原体。本研究旨在开发基于纳米胶囊的可光分解纳米农药，以实现高效的农药控制。
结果：使用负偶氮苯接枝透明质酸（偶氮-HA）和正聚二甲基二烯丙基氯化铵（聚DADMAC）的逐层组装成功地制造了目标纳米农药，由紫外可见，动态光散射,Zeta电位和透射电子显微镜测量。制备的纳米胶囊的粒径和Zeta电位为220nm和+46.1mV,分别,和纳米胶囊被发现保持稳定长达30天。吡虫啉(IMI)在IMI/azo-HA@polyDADMAC中的最佳载药量和包封率分别为21.5%和91.3%,分别。在UV光照射(365nm)时,IMI从纳米农药的累积释放从~50%增加到~95%。在紫外线照射下，纳米农药对蚜虫的半致死浓度（LC50）值从2.22降至0.55mgL-1。
结论：在紫外线照射下，HA分解的IMI/azo-HA@polyDADMAC纳米农药中偶氮基团的反式向顺式转化，从而促进IMI的发布，导致有效控制农药所需的农药浓度降低。我们的工作证明了光响应性纳米胶囊作为可持续农业中有效和生态友好型农药控制的控释纳米载体的巨大潜力。©2024化学工业学会。
结果：使用负偶氮苯接枝透明质酸（偶氮-HA）和正聚二甲基二烯丙基氯化铵（聚DADMAC）的逐层组装成功地制造了目标纳米农药，由紫外可见，动态光散射,Zeta电位和透射电子显微镜测量。制备的纳米胶囊的粒径和Zeta电位为220nm和+46.1mV,分别,和纳米胶囊被发现保持稳定长达30天。吡虫啉(IMI)在IMI/azo-HA@polyDADMAC中的最佳载药量和包封率分别为21.5%和91.3%,分别。在UV光照射(365nm)时,IMI从纳米农药的累积释放从~50%增加到~95%。在紫外线照射下，纳米农药对蚜虫的半致死浓度（LC50）值从2.22降至0.55mgL-1。
结论：在紫外线照射下，HA分解的IMI/azo-HA@polyDADMAC纳米农药中偶氮基团的反式向顺式转化，从而促进IMI的发布，导致有效控制农药所需的农药浓度降低。我们的工作证明了光响应性纳米胶囊作为可持续农业中有效和生态友好型农药控制的控释纳米载体的巨大潜力。©2024化学工业学会。
