Antibacterial Efficiencies of CVD-PECVD Graphene Nanostructures Synthesized onto Glass and Nickel Substrates against Escherichia coli and Staphylococcus aureus Bacteria

Abstract

The antibacterial activity of graphene nanostructures (GrNs) on glass (G) and nickel (Ni) substrates against Escherichia coli ATCC 35218 (Gram-negative) and Staphylococcus aureus ATCC 25923 (Gram-positive) has been researched in this study. GrNs have been synthesized via two different methods, namely, chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD). While the antibacterial effect of CVD-grown graphene nanosheets has been examined according to the number of layers (monolayer/1–2 layers/2–3 layers), the effect of PECVD grown Gr nanowalls on G substrates has been also analyzed at 100, 150, and 200 W radio frequency (RF) powers. For CVD-grown graphene nanosheets, as the number of layers of graphene nanosheets decreased, the cell viability (%) of E. coli decreased from 100% to 51.4%. It has been shown that PECVD graphene nanowalls synthesized onto G substrates, especially at 200 W, exhibited stronger antibacterial activity against E. coli and S. aureus, and the cell viabilities of E. coli and S. aureus decreased from 100% to 25.19% and 100% to 9.02%, respectively. It is concluded that that both the nanowall (3D structure) morphology, which changes significantly with the presence of RF power, and the defects created on the graphene surface using the PECVD method are more effective against E. coli and S. aureus than CVD-grown graphene-based samples (2D-structure).