Inkject Printed Graphene Microelectrodes for Real-Time Impedance Spectroscopy of Neural Cells in Organ-on-a-Chip

This study presents the development and characterization of a graphene-based sensor integrated into a microfluidic chip for real-time monitoring of cell growth and viability. The sensor fabrication involved the metabolization of graphene from graphite using a simple and cost-effective method. The sensor design, created using Solidworks, featured electrodes capable of detecting environmental changes through impedance sensing. A mold was created using a cutter plotter to overcome challenges in achieving the desired sensor shape, and the electrodes were printed on a polyester (PETE) membrane. The conductivity of the electrodes was optimized through annealing, considering the temperature limits of the membrane. Annealing at 150 °C for 40 minutes yielded electrodes with desired conductivity and maintained membrane integrity. Compatibility with cellular growth was confirmed through cell culture experiments. The scaled electrodes were integrated into a microfluidic chip, and their performance was evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The results demonstrated the successful functioning of the electrodes within the chip. The developed graphene-based sensor offers promising applications in cellular studies and biosensing through real-time monitoring of cell growth and viability was achieved by measuring impedance changes resulting from cell attachment.