Large-area chemical vapor deposition-grown monolayer graphene-wrapped silver nanowires for broad-spectrum and robust antimicrobial coating

New types of antimicrobial systems are urgently needed owing to the emergence of pathogenic microbial strains that gain resistance to antibiotics commonly used in daily life and medical care. In this study, we developed for the first time a broad-spectrum and robust antimicrobial thin film coating based on large-area chemical vapor deposition (CVD)-grown graphene-wrapped silver nanowires (AgNWs). The antimicrobial graphene/AgNW hybrid coating can be applied on commercial flexible transparent ethylene vinyl acetate/ polyethylene terephthalate (EVA/PET) plastic films by a full roll-to-roll process. The graphene/AgNW hybrid coating showed broad-spectrum antimicrobial activity against Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus), and fungi (Candida albicans). This effect was attributed to a weaker microbial attachment to the ultra-smooth graphene film and the sterilization capacity of Ag+, which is sustainably released from the AgNWs and presumably enhanced by the electrochemical corrosion of AgNWs. Moreover, the robust antimicrobial activity of the graphene/AgNW coating was reinforced by AgNW encapsulation by graphene. Furthermore, the antimicrobial efficiency could be enhanced to ~100% by water electrolysis by using the conductive graphene/AgNW coating as a cathode. We developed a transparent and flexible antimicrobial cover made of graphene/AgNW/EVA/PET and an antimicrobial denture coated by graphene/ AgNW, to show the potential applications of the antimicrobial materials.