Center for Materials Science and Technology, University of Mysore, 570006, Mysuru, India.
DOS in Earth Science, University of Mysore, 570006, Mysuru, India.
Sci Rep. 2019 Jun 5;9(1):8303. doi: 10.1038/s41598-019-44309-w.
A simple, eco-friendly, and biomimetic approach using Thymus vulgaris (T. vulgaris) leaf extract was developed for the formation of ZnO-Ag nanocomposites (NCs) without employing any stabilizer and a chemical surfactant. T. vulgaris leaf extract was used for the first time, in a novel approach, for green fabrication of ZnO-Ag NCs as a size based reducing agent via the hydrothermal method in a single step. Presence of phenols in T. vulgaris leaf extract has served as both reducing and capping agents that play a critical role in the production of ZnO-Ag NCs. The effect of silver nitrate concentration in the formation of ZnO-Ag NCs was studied. The in-vitro Antimicrobial activity of NCs displayed high antimicrobial potency on selective gram negative and positive foodborne pathogens. Antioxidant activity of ZnO-Ag NCs was evaluated via (2,2-diphenyl-1-picrylhydrazyl) DPPH method. Photocatalytic performance of ZnO-Ag NCs was appraised by degradation of phenol under natural sunlight, which exhibited efficient photocatalytic activity on phenol. Cytotoxicity of the NCs was evaluated using the haemolysis assay. Results of this study reveal that T. vulgaris leaf extract, containing phytochemicals, possess reducing property for ZnO-Ag NCs fabrication and the obtained ZnO-Ag NCs could be employed effectively for biological applications in food science. Therefore, the present study offers a promising way to achieve high-efficiency photocatalysis based on the hybrid structure of semiconductor/metal.
本研究采用简单、环保且仿生的方法，利用百里香（Thymus vulgaris，T. vulgaris）叶提取物，在水热法一步合成中不使用任何稳定剂和化学表面活性剂的情况下，制备了 ZnO-Ag 纳米复合材料（NCs）。百里香叶提取物首次被用于通过水热法一步合成 ZnO-Ag NCs，作为一种基于尺寸的还原剂，这是一种新颖的方法。百里香叶提取物中的酚类物质既作为还原剂又作为封端剂，在 ZnO-Ag NCs 的制备中发挥着关键作用。研究了硝酸银浓度对 ZnO-Ag NCs 形成的影响。NCs 的体外抗菌活性对选择性革兰氏阴性和阳性食源性病原体表现出高抗菌效力。通过（2,2-二苯基-1-苦基肼基）DPPH 法评估了 ZnO-Ag NCs 的抗氧化活性。通过在自然光下降解苯酚评价了 ZnO-Ag NCs 的光催化性能，其对苯酚表现出高效的光催化活性。通过溶血试验评估了 NCs 的细胞毒性。本研究结果表明，含有植物化学物质的百里香叶提取物具有制备 ZnO-Ag NCs 的还原性能，所得 ZnO-Ag NCs 可有效用于食品科学中的生物应用。因此，本研究为基于半导体/金属的杂化结构实现高效光催化提供了一种有前途的方法。
