Department of Marine Chemistry, Khorramshahr University of Marine Science and Technology, PO. Box 669, Khorramshahr, Iran.
Department of Marine Biology, Khorramshahr University of Marine Science and Technology, PO. Box 669, Khorramshahr, Iran.
Sci Rep. 2020 Nov 12;10(1):19615. doi: 10.1038/s41598-020-76726-7.
The present study reports the synergistic antibacterial activity of biosynthesized silver nanoparticles (AgNPs) with the aid of a combination of chitosan and seaweed-derived polyphenols as a green synthetic route. Under optimum synthesis conditions, the rapid color change from yellowish to dark brown and UV-visible absorption peak at 425 confirmed the initial formation of AgNPs. DLS, TEM, XRD, and EDX analyses revealed the spherical shape of pure biogenic AgNPs with a mean diameter size of 12 nm ± 1.5 nm, and a face-centered cubic crystal structure, respectively. FTIR and TGA results indicated the significant contribution of chitosan and polyphenol components into silver ions bioreduction and thermal stability of freshly formed AgNPs. Long-term colloidal stability of AgNPs was obtained after 6-month storage at room temperature. The bio-prepared AgNPs possessed a negative surface charge with a zeta potential value of - 27 mV. In contrast to naked chemical silver nanoparticles, the green Ag nanosamples demonstrated the distinct synergistic antibacterial in vitro toward all selected human pathogens presumably due to the presence of high content of biomolecules on their surface. The results show that synergy between chitosan and polyphenol results in the enhancement of bactericidal properties of biogenic AgNPs. We also highlighted the underlying mechanism involved in AgNPs formation based on nucleophile-electrophile interaction.
本研究报告了在壳聚糖和海藻来源多酚联合作用下，通过绿色合成途径生物合成银纳米粒子（AgNPs）的协同抗菌活性。在最佳合成条件下，AgNPs 的快速颜色变化（从浅黄色变为深棕色）和 425nm 处的紫外-可见吸收峰证实了 AgNPs 的初始形成。DLS、TEM、XRD 和 EDX 分析表明，纯生物合成的 AgNPs 呈球形，平均直径为 12nm±1.5nm，具有面心立方晶体结构。FTIR 和 TGA 结果表明，壳聚糖和多酚成分对银离子的生物还原和新形成的 AgNPs 的热稳定性有重要贡献。AgNPs 在室温下储存 6 个月后仍具有长期胶体稳定性。生物制备的 AgNPs 具有负表面电荷，zeta 电位值为-27mV。与裸露的化学银纳米粒子相比，绿色 Ag 纳米样品对所有选定的人类病原体表现出明显的协同体外抗菌作用，这可能是由于其表面存在高含量的生物分子。结果表明，壳聚糖和多酚之间的协同作用增强了生物合成 AgNPs 的杀菌性能。我们还强调了基于亲核-亲电相互作用的 AgNPs 形成的潜在机制。
