This study compares the sensitivity of interdigitated electrodes (IDEs) used in Electrical Cell-Substrate Impedance Sensing (ECIS). IDEs made of indium tin oxide (ITO) and ITO coated with iridium oxide (IrOx) were used for ECIS measurements with the human breast cancer cell line, MCF-7. The results indicate that IrOx-modified ITO electrodes provide both biocompatibility and higher cell sensitivity compared to ITO electrodes. We also found that the quantity of IrOx required to generate such a sensitivity improvement is sufficiently low to not interfere with the visualization of the cells under study. IrOx-modified ITO electrodes are therefore promising sensors for ECIS applications.
