title: Influence of cell adhesion and spreading on impedance characteristics of cell-based sensors.
abstract: Impedance measurements of cell-based sensors are a primary characterization route for detection and analysis of cellular responses to chemical and biological agents in real time. The detection sensitivity and limitation depend on sensor impedance characteristics and thus on cell patterning techniques. This study introduces a cell patterning approach to bind cells on microarrays of gold electrodes and demonstrates that single-cell patterning can substantially improve impedance characteristics of cell-based sensors. Mouse fibroblast cells (NIH3T3) are immobilized on electrodes through a lysine-arginine-glycine-aspartic acid (KRGD) peptide-mediated natural cell adhesion process. Electrodes are made of three sizes and immobilized with either covalently bound or physically adsorbed KRGD (c-electrodes or p-electrodes). Cells attached to c-electrodes increase the measurable electrical signal strength by 48.4%, 24.2%, and 19.0% for three electrode sizes, respectively, as compared to cells attached to p-electrodes, demonstrating that both the electrode size and surface chemistry play a key role in cell adhesion and spreading and thus the impedance characteristics of cell-based sensors. Single cells patterned on c-electrodes with dimensions comparable to cell size exhibit well-spread cell morphology and substantially outperform cells patterned on electrodes of other configurations.
authors.affiliation: Department of Materials Science & Engineering, University of Washington, Seattle, WA 98195-2120, United States.
authors.forename: Fareid
authors.initials: F
authors.lastname: Asphahani
authors.forename: Myo
authors.initials: M
authors.lastname: Thein
authors.forename: Omid
authors.initials: O
authors.lastname: Veiseh
authors.forename: Dennis
authors.initials: D
authors.lastname: Edmondson
authors.forename: Ryan
authors.initials: R
authors.lastname: Kosai
authors.forename: Mandana
authors.initials: M
authors.lastname: Veiseh
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Miqin
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000295:instrumentation* / Q000379:methods; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D051379:Mice; D008839:Microelectrodes; D041681:NIH 3T3 Cells; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity