Electron Transfer Directed Antibacterial Properties of Graphene Oxide on Metals

Abstract

Nanomaterials such as silver nanoparticles and graphene-based composites are known to exhibit biocidal activities. However, interactions with surrounding medium or supporting substrates can significantly influence this activity. Here, it is shown that superior antimicrobial properties of natural shellac-derived graphene oxide (GO) coatings is obtained on metallic films, such as Zn, Ni, Sn, and steel. It is also found that such activities are directly correlated to the electrical conductivity of the GO-metal systems; the higher the conductivity the better is the antibacterial activity. GO-metal substrate interactions serve as an efficient electron sink for the bacterial respiratory pathway, where electrons modify oxygen containing functional groups on GO surfaces to generate reactive oxygen species (ROS). A concerted effect of nonoxidative electron transfer mechanism and consequent ROS mediated oxidative stress to the bacteria result in an enhanced antimicrobial action of naturally derived GO-metal films. The lack of germicidal effect in exposed cells for GO supported on electrically nonconductive substrates such as glass corroborates the above hypothesis. The results can lead to new GO coated antibacterial metal surfaces important for environmental and biomedical applications.

Implications of Chemical Reduction Using Hydriodic Acid on the Antimicrobial Properties of Graphene Oxide and Reduced Graphene Oxide Membranes

“…The antimicrobial property of graphene‐based materials has been closely linked to their electrical conductivity . The electrical conductivity of the GBMs in this study (Figure g) also correlates well with the antimicrobial activity (Figures and ).…”

“…The antimicrobial property of graphene-based materials has been closely linked to their electrical conductivity. [28,48] The electrical conductivity of the GBMs in this study ( Figure 1g) also correlates well with the antimicrobial activity (Figures 2 and 3). Since no structural damage was observed in the bacterial cell membrane ( Figure S4, Supporting Information), the oxidative stress pathway was hypothesized as the key antimicrobial mechanism.…”

Two‐Dimensional Materials for Antimicrobial Applications: Graphene Materials and Beyond

“…For example, in av ery recent report, Panda et al demonstrated that electron transfer affects the antibacterial properties of shellac-derived GO films on different substrates. [48] They chose severalmetal substrates (Zn, Sn, Ni, steel) as conductive surfaces and glass as an insulating surface for the growth of GO coatings, and found that all bare substrates except Zn did no harm to bacteria. After coating with GO,a ll the conductors becamed etrimental towardb acteria (GO-Zn > GO-Ni > GO-Sn > GO-steel), but GO-glass was still harmless.…”

Graphene and Graphene‐Based Materials in Biomedical Science

“…[246b] Dithiothreitol reduced graphene oxide was synthesized and it showed excellent antimicrobial properties against E. coli . GO–metals composites are used to study the antibacterial poperties of E. coli cells and found GO coated antibacterial metal surfaces are important for biomedical and environmental applications . Visible light‐assisted antibacterial activity by the graphene oxide nanosheets vertically aligned onto copper oxide nanowire arrays has been developed and studied, and it was found to be promising nanostructure device for antimicrobial applications in particular for dry environments .…”

“…[247] GO-metals composites are used to study the antibacterial poperties of E. coli cells and found GO coated antibacterial metal surfaces are important for biomedical and environmental applications. [248] Visible light-assisted antibacterial activity by the graphene oxide nanosheets vertically aligned onto copper oxide nanowire arrays has been developed and studied, and it was found to be promising nanostructure device for antimicrobial applications in particular for dry environments. [249] Silver-decorated sandwich-like mesoporous silica/ reduced graphene oxide nanosheets have been used for the effective study of antibacterial activity toward P. putida, E. coli, and Rhodococcus through photothermal effect.…”