Synthesis, Characterization and Antibacterial Activity of Chlorophyllin Functionalized Graphene Oxide Nanostructures

To enhance the antimicrobial effect of graphene oxide against Escherichia coli, water soluble chlorophyllin and zinc metal ions were used to prepare two types of functionalized GO nanomaterials, namely, graphene oxide-chlorophyllin and graphene oxide-chlorophyllin-Zn. Functionalized graphene oxide were characterized using Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, ultra violet-visible spectroscopy, and field emission scanning electron microscopy. Under similar concentration and incubation conditions, graphene oxide-chlorophyllin-Zn dispersion had the highest antibacterial activity, followed by graphene oxide-chlorophyllin and graphene oxide. Changes in the bacterial cell membrane were also investigated by field emission scanning electron microscopy. The incubation of bacteria with functionalized graphene oxide nanomaterials caused the loss of cellular integrity and consequently, cell death. The results suggested that the surface chemistry and metal toxicity played a major role in making graphene oxide-chlorophyllin-Zn a strong antibacterial agent. Antibacterial mechanisms of the functionalized graphene oxide nanomaterials are proposed.