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Bacterial adhesion to surfaces is the onset of biofilm formation and a hard problem to tackle, aggravated by the rise in drug-resistant bacteria, responsible for more than 500 000 deaths globally/year. This work reports few-layer graphene (FLG) and few-layer graphene oxide (FLGO) as stand-alone light-responsive platforms to develop smart antibacterial surfaces. Films exposure to low-intensity NIR drastically improve their ability to kill planktonic (up to ∼99%) and adherent (up to ∼85%) methicillin-resistant S. aureus and S. epidermidis. Upon irradiation, a mild photothermal effect is observed in supernatant, with temperature rising from 37.0 °C to 39.0 °C–42.0 °C, while surface temperature of non-oxidized FLG films increases to 51.3 °C versus 56.0 °C for oxidized films. Both films prompt total glutathione oxidation when irradiated, despite FLG films induce higher ROS generation than FLGO, suggesting antioxidants depletion occurs preferentially by ROS-dependent pathway (photodynamic effect) for FLG versus ROS-independent pathway for FLGO films. This proof-of-principle study demonstrates that safe, low-intensity NIR irradiation is a valuable and effective tool to boost graphene surfaces’ antibacterial performance through a synergistic photothermal and photodynamic effect. These stand-alone NIR-activated graphene-based platforms arise as simple and economical disinfection surfaces/systems, with widespread use in medical and non-medical applications.

Although graphene-based materials (GBMs) have been thoroughly explored, their use in antimicrobial surfaces is still a developing field. This review overviews the different methods for fabricating GBMs-containing surfaces (free-standing films, coatings or bulk composites) and their antibacterial properties. The difficulty in controlling the broad number of factors affecting interactions between GBMs and bacteria hampers the establishment of clear cause-effect relations. Nevertheless, it is clear that GBMs size, exposure, oxidation, as well as surface conductivity and roughness are the main surface features influencing the antimicrobial properties. Depending on the production method, GBMs basal planes and/or sharp edges are exposed, having a major impact on bacteria through electron transference, piercing of the membrane or pore formation, amongst others. Each of these effects leads to production of oxidative stress and/or bacterial membrane disruption and, consequently, to bacterial death. While oxidized graphene-containing surfaces are antimicrobial when either basal planes or sharp edges are exposed, graphene-containing surfaces are mainly effective when sharp edges are protruding, except for few studies showing effect due to graphene basal planes when coated over conductive materials. As such, this review enlightens and clarifies the surface features most strongly affecting bacteria, providing researchers the necessary tools to produce antibacterial GBMs-containing surfaces with tuned mechanisms of action.