Parylene-C-Coated indium tin oxide electrodes for the optical- and electrical-impedance characterization of cells.

The demand for the label-free and real-time monitoring of biological cells for the diagnosis of diseases and the discovery of new drugs is increasing. The electrical-impedance characterization of cells has been used to quantify in real time the behaviours of biological cells adhered on the gold or platinum microelectrodes. In this article, a parylene-C-coated indium tin oxide (ITO) electrode, which has better transparency than the conventional electrodes, and high biocompatibility, was investigated for the optical- and electrical-impedance characterization of the cell growth. The living cells on the fabricated parylene-C-coated ITO electrode were observed via phase contrast microscopy, which produces high-contrast images of the transparent cells without staining. The electrical properties of the cellular parameters were extrapolated through fitting analysis with the designed equivalent circuit to the measured impedance spectra of the cell-covered electrode. From the experimental results, it was proven that the fabricated parylene-C-coated ITO electrode is feasible for the optical- and electrical-impedance characterization of cell growth.