Do CVD grown graphene films have antibacterial activity on metallic substrates?

TL;DR

This study evaluates the antibacterial activity of CVD-grown graphene films on different metallic substrates, finding no inherent antibacterial effect but observing activity due to copper ion release when on copper substrates.

Contribution

It demonstrates that graphene's antibacterial activity depends on the underlying substrate and ion release, not on the graphene itself.

Findings

Graphene on gold does not affect bacterial viability.

Graphene on copper releases bactericidal cupric ions.

Antibacterial activity correlates with copper ion release, not graphene presence.

Abstract

Accurate assessment of the antibacterial activity of graphene requires consideration of both the graphene fabrication method and, for supported films, the properties of the substrate. Large-area graphene films produced by chemical vapor deposition were grown directly on copper substrates or transferred on a gold substrate and their effect on the viability and proliferation of the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli were assessed. The viability and the proliferation of both bacterial species were not affected when they were grown on a graphene film entirely covering the gold substrate, indicating that conductivity plays no role on bacterial viability and graphene has no antibacterial activity against S. aureus and E. coli. On the other hand, antibacterial activity was observed when graphene coated the copper substrates, resulting from the release of bactericidal cupric ions in inverse proportion to the graphene surface coverage.