title: Surface activation of graphene oxide nanosheets by ultraviolet irradiation for highly efficient anti-bacterials.
abstract: A comprehensive investigation of anti-bacterial properties of graphene oxide (GO) and ultraviolet (UV) irradiated GO nanosheets was carried out. Microscopic characterization revealed that the GO nanosheet-like structures had wavy features and wrinkles or thin grooves. Fundamental surface chemical states of GO nanosheets (before and after UV irradiation) were investigated using x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. Minimum inhibitory concentration (MIC) results revealed that UV irradiated GO nanosheets have more pronounced anti-bacterial behavior than GO nanosheets and standard antibiotic, kanamycin. The MIC of UV irradiated GO nanosheets was 0.125 μg ml⁻¹ for Escherichia coli and Salmonella typhimurium, 0.25 μg ml⁻¹ for Bacillus subtilis and 0.5 μg ml⁻¹ for Enterococcus faecalis, ensuring its potential as an anti-infective agent for controlling the growth of pathogenic bacteria. The minimum bactericidal concentration of normal GO nanosheets was determined to be two-fold higher than its corresponding MIC value, indicating promising bactericidal activity. The mechanism of anti-bacterial action was evaluated by measuring the enzymatic activity of β-D-galactosidase for the hydrolysis of o-nitrophenol-β-D-galactopyranoside.
authors.affiliation: Department of Bionanotechnology, Gachon University, Gyeonggi-do 461-701, Republic of Korea. Department of Chemistry, Université de Montréal, CP 6128, Succursale Centre-ville, Montreal, QC, H3C 3J7, Canada.
authors.forename: Murugan
authors.initials: M
authors.lastname: Veerapandian
authors.forename: Linghe
authors.initials: L
authors.lastname: Zhang
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Krishnamoorthy
authors.forename: Kyusik
authors.initials: K
authors.lastname: Yun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D006108:Graphite / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology*; D013057:Spectrum Analysis; D013499:Surface Properties / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D010087:Oxides; D006108:Graphite