Eco-friendly method for synthesis of zeolitic imidazolate framework 8 decorated graphene oxide for antibacterial activity enhancement

We report a rapid method for synthesis of zeolitic imidazolate framework 8 (ZIF-8)-decorated graphene oxide (GO) composites (ZGO) with good antibacterial properties. The ZGO composites were synthesized at room temperature with low GO to metal salt ratios. The samples were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and surface area analysis. The characterization results show that ZIF-8 with a size of approximately 120 nm is successfully decorated on the surface of GO sheets with the host ZIF-8 framework maintained in the synthesized composite, but there is a significant reduction in the Brunauer–Emmett–Teller surface area. The antibacterial activities of the samples against Escherichia coli ATCC 11229 and Staphylococcus aureus ATCC 6538 as model strains of gram-negative and -positive bacteria, respectively, were determined by disc diffusion and minimum inhibitory concentration (MIC) tests. ZGO-1.0 (1 wt% of ratio of GO to metal salt) shows the highest antibacterial activity with MIC values required to inhibit bacterial growth of E. coli and S. aureus of 5 times lower than those of pristine ZIF-8. Different antibacterial mechanisms are proposed based on field-emission scanning electron microscope images of the two bacteria after contact with the synthesized composite. Overall, owing to the simple synthesis, good stability, low chemical usage, and excellent antibacteri...
Source: Particuology - Category: Science Source Type: research