Comparative electrical impedance spectroscopy study of graphene and indium tin oxide electrodes during low frequency measurements

The four-electrode system is often applied to examine the dielectric properties of biological samples in low frequency range because the four-electrode method can be used to avoid measurement inaccuracies due to electrode polarization. This study is aiming to create four-electrode sensors that can provide reliable data about measuring cells even at low frequencies. Graphene and indium tin oxide (ITO) covered macroelectrodes were fabricated and compared, using electrical impedance spectroscopy (EIS). Impedance measurements were performed with solution series of NaCl. The impedance values of NaCl concentrations were not significantly different for the graphene and ITO electrodes but the standard deviation of data were larger for ITO electrodes than for graphene electrodes. Based on our investigations, the graphene-coated four-electrode sensor can provide cost-effective and sensitive measurements in the study of alpha and beta dispersions of cells.