Influence of the electrode radius on the impedance spectra of cell-covered disc electrode

Non-destructive methods for cell characterization are required, for example, for the evaluation of stem cell differentiations or for the long-term monitoring of (nano) materials in vitro. Microelectrode-based chips and electrical impedance spectroscopy can be used to monitor the growth of human mesenchymal stem cells on electrodes or to investigate effects on cell barrier function and on cell adhesion without any chemical marker. In this article, it was investigated how the area of planar disc electrode affects the impedance of cell-covered electrodes. The sensitivity of impedance measurement with cells (defined as the ratio of the impedance magnitude of electrode with cells to the value without cells) was examined with respect to the electrode radius. Under given conditions, the impedance magnitude of cell-covered electrode was most distinguished from the value of uncovered electrode when the electrode radius was 200 mu m.