紫外光辐射山茱萸水提液制备纳米银及生物活性

利用254 nm紫外光照射山茱萸水提液在室温下制备了纳米银, 并通过UV-Vis光谱检测其在410 nm附近的等离子体共振峰; 研究了溶液pH值、 料液比以及反应时间对还原反应的影响, 确定了纳米银的最优合成条件: pH=7.0, 料液比1∶1, 反应时间1 h. 通过X射线晶体衍射、 透射电子显微镜和激光粒度仪对纳米银的晶体结构、 粒径、 表面性质和形貌等进行表征发现, 在最优反应条件下制得的纳米银为面心立方结构, 呈近球形, 平均粒径(55.4±0.9) nm, 分散均匀, 表面带负电(-10.2 mV), 具有较高的稳定性. 生物活性研究结果表明, 制得的纳米银具有良好的抗氧化、 抗菌及抗癌活性. 当纳米银浓度为62.5 μg/mL时, 对DPPH自由基的清除率为70.0%; 对S. aureus和E. coli最低抑菌浓度分别为3.9和7.8 μg/mL; 对结直肠癌细胞HCT116和SW620的IC₅₀值分别为23.1和35.1 μg/mL.

Novel Biosynthesis Method of Silver Nanoparticle by UV Radiation of Cornus Officinalis Aqueous Extract and Biological Activities †

Owing to the widely applications of silver nanoparticles(AgNPs) in catalysis and biomedicine, researchers have focused their attentions on the formation method. In this work, a green and easy synthesis method of silver nanoparticles(AgNPs) by 254 nm ultraviolet lamp radiation using Cornus officinalis aqueous extract was reported, and the antioxidant, antibacterial and anticancer activities were assessed. The influence of the solution pH(7.0), material proportion(1∶1) and reaction time(1 h) on reduction reaction were discussed to confirm the most efficient reaction condition. X-ray diffraction(XRD), dynamic light scattering and transmission electron microscopy were conducted to investigate the shape, size and surface of the silver nanoparticles, revealing a face-centered cubic(fcc) structure and spherical shape with an average particle size of (55.4±0.9) nm covered by anion(Zeta potential: -10.2 mV). By calculating the free radical scavenging rate for DPPH, the antioxidant activities of AgNPs were assessing. When the concentration of AgNPs increased to 62.5 μg/mL, the free radical scavenging rate was 70% meaning a good antioxidant activity. Furthermore, the AgNPs generated by Cornus officinalis aqueous extract revealed significant inhibition on the growth of S. aureus and E. coli, where the MIC values were 3.9 and 7.8 μg/mL, respectively. The IC₅₀ values for colorectal cancer cell HCT116 and SW620 were 23.1 and 35.1 μg/mL, respectively, indicating a good anticancer activity.