Wrinkled Surface-Mediated Antibacterial Activity of Graphene Oxide Nanosheets

Abstract

Surface wrinkles are commonly observed in large-scale of graphene films. As a new feature, the wrinkled surface of graphene films may directly affect bacterial viability by means of various interactions of bacterial cells with graphene sheets. In the present study, we introduce a wrinkled surface geometry of graphene oxide (GO) thin films for antibacterial application. Highly wrinkled GO films were formed by vacuum filtration of a GO suspension through a prestrained filter. Several types of wrinkled GO surfaces were obtained with different roughness grades determined by root-mean-square values. Antibacterial activity of the fabricated GO films toward three different bacterial species, Escherichia coli, Mycobacterium smegmatis, and Staphylococcus aureus, was evaluated in relation to surface roughness. Because of their nanoscopically corrugated nature, the wrinkled GO films exhibited excellent antibacterial properties. On the basis of our detailed observations, we propose a novel concept of the surrounded contact-based mechanism for antimicrobial activity of wrinkled GO films. It postulates formation of a mechanically robust GO surface "trap" that prompts interaction of bacteria with the diameter-matched GO sink, which results in substantial damages to the bacterial cell membrane. We believe that our approach uncovered a novel use of a promising two-dimensional material for highly effective antibacterial treatment.

Recent Progress in Two‐Dimensional Antimicrobial Nanomaterials

“…Zou et al. synthesized wrinkled GO NSs with hierarchical structures and multiscale lengths by vacuum filtration of GO suspensions through a porous filter membrane (Figure A) . They revealed that the surface roughness of the GO films was associated with their antibacterial performances.…”

“…The unique all‐sp 2 ‐carbon structure of graphene‐based nanosheets (NSs) contributes to strong interactions with bacterial membrane lipids, which facilitate efficient bacterial cell membrane disruption and robust phospholipid extraction . Additionally, ROS produced by graphene oxide (GO) NSs upon light irradiation would also result in serious damage to bacterial cell membranes . The size and surface roughness of GO NSs are determining factors for disinfection efficiency.…”

“…The striking antibacterial capabilities of small‐sized GO NSs may be derived from an oxidative mechanism associated with high defect densities . Wrinkles in GO NSs favor trapping of bacteria with matching diameters, and the abundance of sharp edges facilitates the destruction of cell membranes . The GO/Ag nanohybrid shows similar membrane stress‐dominated antibacterial mechanisms (Figure A).…”

Graphene Materials in Antimicrobial Nanomedicine: Current Status and Future Perspectives

“…[71,80] In addition to AgNP-GO hybrids, several other synergistic mixtures have been developed, including the mixtures of rGO with quaternary phosphonium salts, [69] iodine, [74] and antibiotics. And, subsequent studies have shown that vertically aligned [82] and wrinkled [83] GM surfaces may exhibit higher antibacterial activity compared to horizontal orientation. Early studies on the antimicrobial activity of GMs investigated GO-and rGO-coated surfaces.…”

Interfactant action of an amphiphilic polymer upon directing graphene oxide layer formation on sapphire substrates

“…Following the intended application of GO, reduced GO or graphene films, the morphology of the constituting adsorbed nano-sheets may be aspired to result smooth and flat or, alternatively, corrugated, e.g. wrinkled or crumpled [14][15][16][17]. The interaction between the substrate and graphene or between adsorbed nanoparticles and GO may govern the formation of wrinkles [14,15] in the flexible nano-sheets.…”