Biogenic methods of synthesis of nanoparticles (NPs) using plant extracts have been given a great attention due to its nontoxicity and environmental friendliness. In this study, TiO₂ NPs were synthesized from titanium tetrabutoxide and extract of root of Kniphofia foliosa. NPs of TiO₂ were biosynthesized at different volume compositions of titanium tetrabutoxide to the plant extract with a ratio of 1 : 2, 1 : 1, and 2 : 1, respectively. These green synthesized NPs of TiO₂ were characterized by thermogravimetric analysis (TGA/DTA), X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy. TGA/DTA analysis has confirmed that the synthesized NPs of TiO₂ were stable above the temperature of 500°C. The sharp and intense peaks at 2θ values of 25.3, 38.0, 47.9, 53.2, 54.8862, 62.7, 70.2, and 75.0 have confirmed formation of crystalline NPs of TiO₂ in the sample of 1 : 1 and 2 : 1 ratios, and less crystalline samples for TiO₂ NPs prepared in a 1 : 2 ratio. Comparison between FT-IR absorption bands of the plant extract and that of calcined NPs of TiO₂ confirmed the purity of synthesized nanomaterials, except unavoidable adsorption of moisture on the surface of TiO₂ NPs in an open air. The antibacterial activity of biosynthesized TiO₂ NPs and that of ethanolic root extract of Kniphofia foliosa was investigated via the disc diffusion method against human pathogen bacteria strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Streptococcus pyogenes. Among the different ratios, TiO₂ (1 : 1) NP shows better performance towards Gram-negative bacteria due to its smaller average crystalline size and uniform morphology observed in SEM image relative to the other two ratios of TiO₂ NPs. Antibacterial activity of the ethanolic root extract of Kniphofia foliosa itself showed better performance towards Gram-negative bacteria than NPs of TiO₂ that might be due to antibacterial activity of residue of ethanol left with the plant extract.

中文翻译：

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以剑叶根提取物为模板合成纳米氧化钛及其表征及在耐药菌中的应用

由于其无毒且对环境友好，因此使用植物提取物合成纳米颗粒（NPs）的生物方法已受到广泛关注。本研究采用四丁氧基钛和叶锦根提取物合成了TiO ₂ NPs 。TiO _2的NPs以不同体积的四丁氧基钛生物合成到植物提取物中，比例分别为1：2、1：1和2：1。这些绿色合成的TiO ₂ NP通过热重分析（TGA / DTA），X射线衍射（XRD），扫描电子显微镜-能量色散X射线光谱（SEM-EDS），透射电子显微镜（TEM），紫外可见光谱（UV-Vis）进行表征）和傅立叶变换红外（FTIR）光谱。TGA / DTA分析已经证实，合成的TiO ₂ NP在高于500℃的温度下是稳定的。在2个的尖锐和强峰θ 75.0 25.3值，38.0，47.9，53.2，54.8862，62.7，70.2，并已证实形成的TiO结晶NP的₂ 1和2：1的样品中的1分比，和少TiO _2的晶体样品以1：2的比例制备的NP。比较植物提取物的FT-IR吸收带和煅烧的TiO ₂ NPs的红外吸收谱带，证实了合成的纳米材料的纯度，除了在露天中不可避免地吸附了TiO ₂ NPs表面的水分。圆盘扩散法研究了合成的TiO ₂ NPs和叶菜乙醇根提取物对金黄色葡萄球菌，大肠埃希菌，肺炎克雷伯菌和化脓性链球菌的病原菌的抗菌活性。在不同比例中，TiO ₂（1：1）NP对革兰氏阴性细菌表现出更好的性能，这是因为相对于其他两种TiO ₂ NPs ，其平均晶体尺寸较小，并且在SEM图像中观察到的形态均一。Kniphofia foliosa的乙醇根提取物本身的抗菌活性比TiO ₂ NPs对革兰氏阴性细菌表现出更好的性能，这可能是由于植物提取物残留的乙醇残留物具有抗菌活性。