氧化锌纳米颗粒的形貌控制合成及其体外抗菌活性

Morphology controlled synthesis of ZnO nanoparticles for in-vitro evaluation of antibacterial activity

在不使用任何表面活性剂或模板的情况下,采用可控沉淀法在水溶液中成功合成形貌均匀的分层花状和纳米棒状氧化锌(ZnO)。为了阐明纳米颗粒的生长机理,系统研究pH、反应时间和温度对纳米颗粒形貌的影响。采用SEM、FT-IR和XRD等表征手段对样品进行分析。XRD谱证实合成的粉末具有良好的结晶性。此外,对比研究合成的花状(ZnO-1)和纳米棒状(ZnO-2)的ZnO纳米颗粒与商业ZnO(ZnO-Com)颗粒的体外抗菌活性。结果表明,在实验条件下,ZnO-2比ZnO-1对受试菌具有更高的抗菌活性,而商业ZnO则没有抗菌活性。当ZnO-2的浓度从0.25升高到0.75μg/μL时,对变异链球菌的抑菌环从约30 mm扩大到33 mm,对大肠杆菌的抑菌环从约28mm增大到30mm。研究表明,合成的氧化锌纳米颗粒作为抗菌剂,可能在生物医学方面有效抑制某些致病菌。

Novel hierarchical flower-and nanorod-shaped ZnO nanoparticles with uniform morphological features were successfully synthesized through controlled precipitation method in aqueous media without using any surfactant or template.To elucidate the growth mechanism of the synthesized nanoparticles,the effects of pH,reaction time and temperature were studied systematically.Selected ZnO samples were then subjected to SEM,FT-IR and XRD analysis.XRD patterns confirmed well crystalline nature of the as-synthesized powders.Furthermore,synthesized nanoparticles(hierarchical flowers as ZnO-1 and nanorods as ZnO-2),as well as commercial ZnO(ZnO-Com),were then investigated for in-vitro evaluation of antibacterial activity against various bacterial strains of clinical importance.Results showed that ZnO-2 exhibited higher antibacterial activity to all tested strains than ZnO-1,while ZnO-Com showed no antibacterial response in the applied experimental conditions.In addition,ZnO concentration-dependent antibacterial study unfolded that size of inhibition zones increased significantly from^30 to 33 mm against Streptococcus mutans and from^28 to 30 mm against Escherichia coli with increasing ZnO-2 concentration from 0.25 to 0.75μg/μL.The present study,therefore,suggests that the application of synthesized ZnO nanoparticles as the antibacterial agent may be effective for inhibiting certain pathogenic bacteria in biomedical sides.