Host-mediated biofilm forming promotes post-graphene pathogen expansion via graphene micron-sheet

Graphene is a potential candidate for applications in biomedical field.It is inevitable that graphene is in contact with the ubiquitous bacterial environment.More attention has been paid to the antimicrobial activity of graphene derivatives(graphene oxide,reduced graphene oxide)than the interaction between graphene and bacteria.Herein,we explore interaction between graphene micron-sheet and bacteria from micro(gene expression)and macro(colonies)perspectives.Results demonstrate that graphene micron-sheet accelerates the biofilm forming thus promoting pathogen expansion toward both Gram-negative bacteria E.coli and Gram-positive bacteria S.aureus.The graphene micron-sheet acts as a“habitat”for increasing bacterial attachment and biofilm forming.For E.coli,graphene micron-sheet,firstly changes the integrity of periplasmic and outer membrane components,then makes membraneassociated and cell division genes increased,and finally promotes bacterial proliferation;For S.aureus,graphene micron-sheet can accelerate biofilm forming and develop bacterial expansion owing to the regulation of the quorum-sensing system and global regulatory proteins.The work can shed new light on the range of possible mode of actions,developing a better understanding of the capabilities of graphene micronstructures.