Comparative investigation on antibacterial studies of Oxalis corniculata and silver nanoparticle stabilized graphene surface

In this study, we report a facile method for the partial exfoliation of graphite into graphene and simultaneous surface stabilization of graphene and silver nanoparticles using a plant extract from Oxalis corniculata (Puliyarai Keerai). Four graphene composites were prepared through sonication: graphene-plant extract prepared at room temperature of about 27 degrees C (G-PRT) and 70 degrees C (G-PHT), and graphene-plant extract with silver nanoparticles prepared using NH4OH (G-PAgNH4) and NaOH (G-PAgNa). The composites were characterized using X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analyses. The characterizations revealed the small sizes of the graphene sheets in the composites than in graphite, silver nanoparticles (AgNPs) with diameters of similar to 10 nm, and uniform distributions of the plant extract and AgNPs on the graphene surface. The graphene composites exhibited significant antibacterial potential against both Gram-negative (Salmonella typhimurium and Escherichia coli) and Gram-positive (Bacillus cereus and Staphylococcus aureus) microorganisms. G-PAgNa composites exhibited the lowest (10 mu g/mL) minimum inhibitory concentration and minimum bacterial concentration values against S. aureus and S. typhimurium. [GRAPHICS] .