Effect of electrode material on the sensitivity of interdigitated electrodes used for Electrical Cell-Substrate Impedance Sensing technology.

This study explores the effect of the electrode material on the sensitivity of interdigitated electrodes (IDEs) used in Electrical Cell-Substrate Impedance Sensing (ECIS) technology. This technique is a label-free method to evaluate cellular activity of adherent cells. IDEs of gold (Au), indium tin oxide (ITO) and ITO functionalized with iridium oxide (IrOx) were characterized with impedance spectroscopy and their interfacial impedances were evaluated in potassium chloride (KCl) solutions. In parallel, ECIS measurements were performed on these three electrode materials during the proliferation of the human breast cancer cell line, MCF-7. The results indicate that the difference in sensitivity to MCF-7 of the three materials might be strongly correlated to their interfacial impedances. We found that ITO electrodes coated with IrOx show slightly higher sensitivity to MCF-7 breast cancer cells while still offering transparency compared to gold, which is considered the conventional material in ECIS devices.