title: Size-dependent antimicrobial response of zinc oxide nanoparticles.
abstract: Antibacterial and antifungal activities of zinc oxide nanoparticles (ZnO NPs) were investigated against infectious microorganisms. ZnO NPs were prepared by wet chemical precipitation method varying the pH values. Particle size and morphology of the as-prepared ZnO powders were characterised by X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscope. The zone of inhibition by NPs ranged from 0 to 17 mm. The lowest minimum inhibitory concentration value of NPs is 25 µg.ml(-1) against Staphylococcus epidermidis. These studies demonstrate that ZnO NPs have wide range of antimicrobial activities towards various microorganisms. The results obtained in the authors' study indicate that the inhibitory efficacy of ZnO NPs is significantly dependent on its chosen concentration and size. Significant inhibition in antibacterial response was observed for S. epidermidis when compared with control antibiotic.
authors.affiliation: Crystal Growth Centre, Anna University, Chennai 600025, India.
authors.forename: Loganathan
authors.initials: L
authors.lastname: Palanikumar
authors.affiliation: Crystal Growth Centre, Anna University, Chennai 600025, India. sinna_ramasamy@yahoo.com.
authors.forename: Sinna Nadar
authors.initials: SN
authors.lastname: Ramasamy
authors.affiliation: Division of Microbiology, Entomology Research Institute, Loyola College, Chennai 600034, India.
authors.forename: Chandrasekaran
authors.initials: C
authors.lastname: Balachandran
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D000935:Antifungal Agents / Q000737:chemistry*; D001419:Bacteria / Q000187:drug effects*; D004058:Diffusion; D005658:Fungi / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D010316:Particle Size; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013696:Temperature; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D015034:Zinc Oxide