Laser ablation produced graphene/MOF-۵ nanocomposite: antibacterial properties

Preparation of graphene decorated MOF-۵ nanocomposite by pulsed laser ablation (PLA) method in liquid environment has been investigated for the first time. Firstly, MOF-۵ nanostructures were synthesized by irradiating a high-purity zinc (Zn) plate in dimethylformamide (DMF) solution containing terephthalic acid ligand with Nd:YAG pulsed laser. Using the fundamental wavelength of Nd:YAG laser at ۱۰۴۶ nm and pulse width of ۷ ns, three samples of MOF-۵ nanostructures were produced in the solutions with three ligand concentrations. Then, by laser ablation of a graphite target in the MOF-۵ nanostructures suspensions, graphene/MOF-۵ nanocomposites were produced. Furthermore, the antibacterial activity of the samples was evaluated against Escherichia coli (E. coli) as a gram-negative and Staphylococcus aureus (S. aureus) as a gram-positive bacterium. Morphology of MOF-۵ nanostructures was modified due to presence of graphene nanosheets in the structure of nanocomposite. TEM images show that square shape MOF-۵ particles were located on the surface of graphene nanosheets. Concentration of synthesized samples was increased with increasing the ligand concentration in the liquid environment of ablation. And stronger antibacterial effects of nanocomposites were observed against the gram-negative bacteria due to their gravitation of opposite charges.