title: Toxicity of graphene nanoflakes evaluated by cell-based electrochemical impedance biosensing.
abstract: Graphene nanoflake toxicity was analyzed using cell-based electrochemical impedance biosensing with interdigitated indium tin oxide (ITO) electrodes installed in a custom-built mini-incubator positioned on an inverted optical microscope. Sensing with electrochemical measurements from interdigitated ITO electrodes was highly linear (R(2) = 0.93 and 0.96 for anodic peak current (Ipa) and cathodic peak current (Ipc), respectively). Size-dependent analysis of Graphene nanoflake toxicity was carried out in a mini-incubator system with cultured HeLa cells treated with Graphene nanoflakes having an average size of 80 or 30 nm for one day. Biological assays of cell proliferation and viability complemented electrochemical impedance measurements. The increased toxicity of smaller Graphene nanoflakes (30 nm) as measured by electrochemical impedance sensing and optical monitoring of treated cells was consistent with the biological assay results. Cell-based electrochemical impedance biosensing can be used to assess the toxicity of nanomaterials with different biomedical and environmental applications.
authors.affiliation: School of Advanced Materials Science and Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, Korea.
authors.forename: Ok Ja
authors.initials: OJ
authors.lastname: Yoon
authors.forename: Insu
authors.initials: I
authors.lastname: Kim
authors.forename: Il Yung
authors.initials: IY
authors.lastname: Sohn
authors.forename: Truong Thuy
authors.initials: TT
authors.lastname: Kieu
authors.forename: Nae-Eung
authors.initials: NE
authors.lastname: Lee
mesh_terms: D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy / Q000379:methods*; D006108:Graphite; D006367:HeLa Cells; D006801:Humans; D049329:Nanostructures; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D006108:Graphite
keywords: HeLa cells; ITO electrode; electrochemical impedance biosensor; graphene; toxicity analysis