title: Direct and indirect sonication affect differently the microstructure and the morphology of ZnO nanoparticles: Optical behavior and its antibacterial activity.
abstract: In the present study, the sono-synthesis of ZnO nanoparticles (NPs) was performed by simple, low-cost, and the environmentally friendly method. The synthesis of zinc oxide as an antibacterial agent was performed by an ultrasonic bath (low intensity) for the indirect sonication and a horn system (high intensity) for the direct sonication. The samples synthesized by these two kinds of sonication were compared with each other. Crystallographic structures and the morphologies of the resultant powders were determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns showed that both ZnO samples were crystallized in their pure phase. The TEM images confirmed that the morphologies of the products were completely different from each other. Based on the obtained analysis, the probable growth mechanisms were proposed for crystallization of both samples. The antibacterial activity of the synthesized species was evaluated by the colony count method against Escherichia coli O157:H7. Moreover, the optical behavior of the samples was studied by UV-vis spectroscopy and the variation of the ZnO band gap was compared.
authors.affiliation: Sonochemical Research Center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, 91779, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Sharifalhoseini
authors.affiliation: Sonochemical Research Center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, 91779, Mashhad, Iran; Environmental Chemistry Research Center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, 91779, Mashhad, Iran. Electronic address: entezari@um.ac.ir.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Entezari
authors.affiliation: Biochemical Research Center, Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, 91779, Mashhad, Iran.
authors.forename: Razieh
authors.initials: R
authors.lastname: Jalal
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000737:chemistry*; D055620:Optical Phenomena; D013010:Sonication; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015034:Zinc Oxide
keywords: Green method; Optical behavior; Sono-synthesis; ZnO NPs