Department of Bioinformatics, Alagappa University, Karaikudi 630003, Tamil Nadu, India.
Department of Chemistry, Arumugam Seethaiyammal Arts and Science College, Tiruppattur, Tamil Nadu, India.
Mater Sci Eng C Mater Biol Appl. 2019 Jun;99:202-210. doi: 10.1016/j.msec.2019.01.105. Epub 2019 Jan 25.
Greener nanotechnology plays an important role in developing alternative and effective treatment strategies for various diseases. Biological synthesis of metal nanoparticles (MNPs) has known to possess suitable alternatives than the existing chemical methods. Greener synthesis of MNPs by using plant extracts has become an emerging field due to their safe, eco-friendly and non-toxic nature that are suitable for synergistic biological activities. Hence, the greener method is chosen by the present study. In the present study, the greener synthesis of gold nanoparticles (AuNPs) was successfully done by using Coleus aromaticus leaf extract at three different temperatures (30 °C, 60 °C and 100 °C). The formation of AuNPs was initially monitored by visual observation and then characterized with the help of diverse techniques like UV-Vis spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), High Resolution-Transmission Electron Microscopy (HR-TEM) and dynamic light scattering (DLS). Surface plasmon resonance (SPR) peak and crystalline nature of AuNPs were obtained by UV-Vis and XRD spectroscopies respectively. FT-IR analysis shows the different characteristic functional groups in turn responsible for the bio-reduction of gold ions by using leaf extract. The formations of different nano-sized AuNPs with their different morphologies were observed by SEM and HR-TEM analyses. Surface charge and stability of the AuNPs were measured by zeta potential and DLS respectively. The synthesized AuNPs coated with cotton fabric was analyzed by UV-Diffuse Reflectance Spectroscopy (UV-DRS), which revealed excellent UV protection against UV radiation. The AuNPs coated cotton fabric exhibited remarkable antibacterial sensitivity against Staphylococcus epidermidis and Escherichia coli. Further, the synthesized AuNPs showed significant cytotoxicity against human liver cancer (HepG2) cell line. The findings of this study revealed that, AuNPs synthesized using Coleus aromaticus leaf extract could be an alternative, safe, and effective source of UV protection, antibacterial and anticancer agents.
绿色纳米技术在开发各种疾病的替代和有效治疗策略方面发挥着重要作用。与现有的化学方法相比，金属纳米粒子（MNPs）的生物合成具有合适的替代品。由于其安全、环保和无毒的特性，适用于协同的生物活性，因此使用植物提取物进行 MNPs 的绿色合成已成为一个新兴领域。因此，本研究选择了绿色方法。在本研究中，成功地使用罗勒叶提取物在三种不同温度（30°C、60°C 和 100°C）下合成了金纳米粒子（AuNPs）。AuNPs 的形成最初通过肉眼观察进行监测，然后借助多种技术进行表征，如紫外-可见分光光度法（UV-Vis）、X 射线衍射（XRD）、傅里叶变换红外（FT-IR）光谱、扫描电子显微镜（SEM）、高分辨率-透射电子显微镜（HR-TEM）和动态光散射（DLS）。表面等离子体共振（SPR）峰和 AuNPs 的结晶性质分别通过紫外-可见光谱和 XRD 光谱获得。FT-IR 分析表明，不同的特征官能团依次负责使用叶提取物还原金离子。通过 SEM 和 HR-TEM 分析观察到不同纳米尺寸的 AuNPs 及其不同形态的形成。通过 zeta 电位和 DLS 分别测量 AuNPs 的表面电荷和稳定性。用紫外漫反射光谱（UV-DRS）分析涂覆有棉织物的合成 AuNPs，结果表明其对紫外线辐射具有优异的紫外线防护性能。涂覆有 AuNPs 的棉织物对表皮葡萄球菌和大肠杆菌表现出显著的抗菌敏感性。此外，合成的 AuNPs 对人肝癌（HepG2）细胞系表现出显著的细胞毒性。本研究的结果表明，使用罗勒叶提取物合成的 AuNPs 可以作为一种替代、安全、有效的紫外线防护、抗菌和抗癌剂来源。
