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.

Synthesis, Characterization and Antibacterial Study of Copper Oxide-Graphene Nanocomposites

“…The response of using graphene oxide on microorganisms has been studied extensively. However, the satisfactory results of metal oxide and graphene oxide nanocomposites have not been reported so far [17][18][19][20][21].In continuation to our earlier studies [22][23][24][25][26][27][28], in present study, we have focused on the synthesis of CuO nanoparticles by facile and cost effective sol-gel method and nanocomposite of copper were prepared with reduced graphene oxide. Antibacterial properties of the synthesized nanoparticles and nano- composites were investigated against Gram-positive and Gramnegative bacteria.…”

“…The response of using graphene oxide on microorganisms has been studied extensively. However, the satisfactory results of metal oxide and graphene oxide nanocomposites have not been reported so far [17][18][19][20][21].…”

Graphene Materials in Antimicrobial Nanomedicine: Current Status and Future Perspectives

“…For example, Veerapandian et al [133] and Hui et al [60] (for GQDs) compared the GO susceptibility of four species in their studies. This can be understood in two ways.…”

The Antibacterial Applications of Graphene and Its Derivatives

“…(4) Photothermal: GO may be used as a photo‐absorbing agent for photothermal therapy (PTT) to generate heat from NIR or other laser energy. The synergistic effects of GO and laser energy greatly enhances antibacterial activity . (5) The basal plane: The antibacterial activity of GO sheets showed dependence on their lateral dimension in E. coli suspensions ( Figure ).…”