title: Phytotoxicity of soluble graphitic nanofibers to model plant species.
abstract: Carbon nanomaterials are considered promising for applications in energy storage, catalysis, and electronics. This has motivated study of their potential environmental toxicity. Recently, a novel nanomaterial consisting of graphene oxide wrapped around a carbon nanotube (CNT) core was synthesized. The resulting soluble graphitic nanofibers were found to have superior catalytic properties, which could result in their use in fuel cells. Before this material undergoes widespread use, its environmental toxicity must be determined because of its aqueous solubility. The authors used the plant species Lolium multiflorum, Solanum lycopersicum, and Lactuca sativa to study the toxicity of the soluble graphitic nanofibers, as well as multiwalled carbon nanotubes (MWCNTs) and graphene oxide, all synthesized in-house. Soluble graphitic nanofiber-exposed plant roots and shoots showed decreased growth, with roots showing more toxicity than shoots. Decreased pH of nanomaterial solutions corresponded to insignificantly decreased root growth, suggesting that another mechanism of toxicity must exist. Agglomeration and adsorption of soluble graphitic nanofibers onto the roots likely caused the remaining toxicity because a gray layer could be seen around the surface of the root. Multiwalled carbon nanotubes showed little toxicity over the concentration range tested, whereas graphene oxide showed a unique pattern of high toxicity at both the lowest and highest concentrations tested. Overall, soluble graphitic nanofibers showed moderate toxicity between that of the more toxic graphene oxide and the relatively nontoxic MWCNTs. Environ Toxicol Chem 2016;35:2941-2947. © 2016 SETAC.
authors.affiliation: Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, North Carolina, USA.|Department of Chemistry, Duke University, Durham, North Carolina, USA.
authors.forename: Danielle E
authors.initials: DE
authors.lastname: Gorka
authors.affiliation: Department of Chemistry, Duke University, Durham, North Carolina, USA.
authors.forename: Jonathan Litvak
authors.initials: JL
authors.lastname: Jeger
authors.affiliation: Department of Chemistry, Duke University, Durham, North Carolina, USA.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Duke University, Durham, North Carolina, USA.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, North Carolina, USA.|Department of Biology, Duke University, Durham, North Carolina, USA.|Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana, USA.
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Colman
authors.affiliation: Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, North Carolina, USA.|Department of Biology, Duke University, Durham, North Carolina, USA.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Bernhardt
authors.affiliation: Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, North Carolina, USA.|Department of Chemistry, Duke University, Durham, North Carolina, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D002384:Catalysis; D006108:Graphite / Q000737:chemistry / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D008129:Lolium / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D057139:Nanofibers / Q000737:chemistry / Q000633:toxicity*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012995:Solubility; D013059:Spectrum Analysis, Raman
chemical_list: D037742:Nanotubes, Carbon; D010087:Oxides; D006108:Graphite
keywords: Carbon nanotube; Graphene oxide; Lolium multiflorum; Toxicity