Antifungal graphene oxide-borneol composite

Abstract

Although antibacterial activities of graphene oxide (GO) and its derivatives have been investigated comprehensively, their antifungal properties are still less reported. Yet, fungal contamination seriously threatens the public health. Herein, we present a design of graphene oxide-borneol (GOB) composite, and report its great antifungal effect. This GOB composite is prepared by esterification of borneol with thiomalic-acid-modified GO sheets, where the linker molecule is used to increase surface carboxyl groups. As a result, the antifungal activity displays a dramatically conversion from no activity of GO and its derivatives to distinct antifungal adhesion and growth inhibition of the GOB. Under microscopy, few spores can be found on the GOB surface, while large numbers of sporangia and spores adhere and grow on the control groups. It is also worth noting that on the GOB sample the fallen spore does not germinate even after 5days, demonstrating a long-term antifungal effect of the GOB composite. Further studies confirm that carbon stereochemistry rather than wettability plays a crucial role on the antifungal adhesion properties. This study not only highlights a promising GOB composite as a candidate of graphene-based antifungal agent, but also provides us with in-depth understanding of the interactions between fungi and graphene-based materials.

Keywords: Antifungal activity; Borneol; Composite; Graphene oxide; Stereochemistry.