Toward development of dual optical and electrical cell-based biosensor: An investigation on electrode geometry and transparent conductive material function

Herein is explored a dual optical and electrical cell based biosensor that can provide insights into cellular events. The fabrication steps along with the electrical characterization of the microelectrodes is described. Initial experiments show that the ability of indium tin oxide (ITO) to detect biological cells at the electrode-cell layer interface mainly depends on the size of sensing area. Following this, the impact of conductivity was also explored to assess the real time impedance signal during the adhesion of a non-confluent layer of the cells on different substrates. Electrodes with a higher conductivity than ITO gave much higher senstivity of impedance changes which allowed the dynamics of subtle cellular morphology changes to be monitored at densities far lower than a confluent layer of cells. Finally, the capability of ITO and gold microelectrode as a functional readout for G protein couple receptor activation were determined. These set of analyses highlighted the challenges and opportunities of ITO substrate as a dual cell-based assay for quantitative analysis of subtle changes in cell morphology.