Ramani Meghana, Ponnusamy S, Muthamizhchelvan C, Marsili Enrico
Center for Materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur, Kancheepuram (D.t.), Chennai 603203, Tamil Nadu, India.
Center for Materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur, Kancheepuram (D.t.), Chennai 603203, Tamil Nadu, India.
Colloids Surf B Biointerfaces. 2014 May 1;117:233-9. doi: 10.1016/j.colsurfb.2014.02.017. Epub 2014 Mar 4.
ZnO nanostructures (ZnO-NSs) of different morphologies are synthesized with the amino acids L-alanine, L-threonine, and L-glutamine as capping agents. X-ray diffraction (XRD) shows the formation of a crystalline wurtzite phase of ZnO-NSs. The surface modification of ZnO-NSs due to the capping agents is confirmed using Fourier transform infrared (FTIR) spectroscopy. Photoluminescence spectroscopy reveals that the concentration of surface defects correlates positively with the number of polar facets in ZnO-NSs. The antimicrobial activity of the ZnO-NSs has been tested against Escherichia coli and the common pathogens Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis. Culture-based methods in rich medium show up to 90% growth inhibition, depending on the ZnO-NSs. Flow cytometry analyses indicate that the reactive oxygen species (ROS) generated by ZnO-NSs contribute mostly to the antibacterial activity. Control experiments in minimal medium show that amino acids and other reducing agents in Luria-Bertani (LB) medium quench ROS, thereby decreasing the antimicrobial activity of the ZnO-NSs.
以氨基酸L-丙氨酸、L-苏氨酸和L-谷氨酰胺作为封端剂，合成了不同形态的氧化锌纳米结构（ZnO-NSs）。X射线衍射（XRD）表明形成了ZnO-NSs的晶体纤锌矿相。使用傅里叶变换红外（FTIR）光谱证实了由于封端剂导致的ZnO-NSs的表面改性。光致发光光谱表明，表面缺陷的浓度与ZnO-NSs中极性面的数量呈正相关。测试了ZnO-NSs对大肠杆菌以及常见病原体金黄色葡萄球菌、肺炎克雷伯菌和枯草芽孢杆菌的抗菌活性。在丰富培养基中基于培养物的方法显示，根据ZnO-NSs的不同，生长抑制率高达90%。流式细胞术分析表明，ZnO-NSs产生的活性氧（ROS）主要促成了抗菌活性。在基本培养基中的对照实验表明，Luria-Bertani（LB）培养基中的氨基酸和其他还原剂会淬灭ROS，从而降低ZnO-NSs的抗菌活性。
