Toxicity of Graphene Shells, Graphene Oxide, and Graphene Oxide Paper Evaluated with Escherichia coli Biotests

• Published in: BioMed research international Vol. 2015; no. 2015; pp. 1 - 10
• Main Authors: Deryabin, Dmitry, Rakov, Eduard G., Vasilchenko, Alexey S., Efremova, Ludmila V.
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2015; Hindawi Limited
• Subjects: Bacteria; Bioassays; Biocompatibility; Biological activity; Carbon; Cell Survival - drug effects; Contact angle; E coli; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - ultrastructure; Graphene; Graphite - toxicity; Membranes; Microscopy; Microscopy, Atomic Force; Nanomaterials; Nanoshells - toxicity; Nanostructures - toxicity; Oxidative Stress - drug effects; Oxides; Oxides - toxicity; Reactive Oxygen Species; Sulfur; Toxicity
• ISSN: 2314-6133; 2314-6141
• DOI: 10.1155/2015/869361

The plate-like graphene shells (GS) produced by an original methane pyrolysis method and their derivatives graphene oxide (GO) and graphene oxide paper (GO-P) were evaluated with luminescent Escherichia coli biotests and additional bacterial-based assays which together revealed the graphene-family nanomaterials’ toxicity and bioactivity mechanisms. Bioluminescence inhibition assay, fluorescent two-component staining to evaluate cell membrane permeability, and atomic force microscopy data showed GO expressed bioactivity in aqueous suspension, whereas GS suspensions and the GO-P surface were assessed as nontoxic materials. The mechanism of toxicity of GO was shown not to be associated with oxidative stress in the targeted soxS::lux and katG::lux reporter cells; also, GO did not lead to significant mechanical disruption of treated bacteria with the release of intracellular DNA contents into the environment. The well-coordinated time- and dose-dependent surface charge neutralization and transport and energetic disorders in the Escherichia coli cells suggest direct membrane interaction, internalization, and perturbation (i.e., “membrane stress”) as a clue to graphene oxide’s mechanism of toxicity.