Surface-anchored Carbon Nanomaterials for antimicrobial surfaces

Abstract

Carbon nanomaterials (CNM) are known for their antimicrobial (antibacterial, antiviral) activity when dispersed in a liquid, but whether this can be transferred to the surface of common materials has rarely been investigated. We have compared two typical CNM (double-walled carbon nanotubes and few-layer graphene) in their non-oxidised and oxidised forms in terms of their antibacterial (Pseudomonas aeruginosa, Staphylococcus aureus) and antiviral (SARS-CoV2) activity after anchoring them on the surface of silicone. We propose a very simple and effective way to entrap CNM on the surface of two different silicone materials and demonstrate that the nanomaterials are anchored within the polymer while still in contact with bacteria. We also investigated their antiviral activity against SARS-COV2 after deposition on standard surgical respiratory masks. Our results show that while suspensions of double-walled carbon nanotubes had a moderate effect on P. aeruginosa, this was not transferred after anchoring them to the surface of silicone. On the contrary, graphene oxide showed a very strong antibacterial effect on P. aeruginosa and oxidised double-walled carbon nanotubes on S. aureus only when anchored to the surface. No significant antiviral activity was observed. This work paves the way for new antibacterial surfaces based on CNM.