New Microfluidic System for Electrochemical Impedance Spectroscopy Assessment of Cell Culture Performance: Design and Development of New Electrode Material

Abstract

Electrochemical impedance spectroscopy (EIS) is widely accepted as an effective and non-destructive method to assess cell health during cell-culture. However, there is a lack of compact devices compatible with microfluidic integration and microscopy that could provide the real-time and non-invasive monitoring of cell-cultures using EIS. In this paper, we reported the design and characterization of a modular EIS testing system based on a patented technology. This device was fabricated using easily processable methodologies including screen-printing of the impedance electrodes and molding or micromachining of the cell culture chamber with an easy assembly procedure. Accordingly, to obtain processable, biocompatible and sterilizable electrode materials that lower the impact of interfacial impedance on TEER (Transepithelial electrical resistance) measurements, and to enable concomitant microscopy observations, we optimized the formulation of the electrode inks and the design of the EIS electrodes, respectively. First, electrode materials were based on carbon biocompatible inks enriched with IrOx particles to obtain low interfacial impedance electrodes approaching the performances of classical non-biocompatible Ag/AgCl second-species electrodes. Secondly, we proposed three original electrode designs, which were compared to classical disk electrodes that were optically compatible with microscopy. We assessed the impact of the electrode design on the response of the impedance sensor using COMSOL Multiphysics. Finally, the performance of the impedance spectroscopy devices was assessed in vitro using human airway epithelial cell cultures.

Electrochemical Biosensing of Glucose Based on the Enzymatic Reduction of Glucose

“…In the same way, the reduction peak shifted to the negative’s values, and its intensity increased in absolute terms. These shifts of the oxidative and reduction peaks and the increasing of the current intensity indicate that an oxidative polymerization was taking place and that more electroactive species were being deposited on the surface of the electrode [ 26 , 33 , 34 ].…”

A Review on Microfluidics-Based Impedance Biosensors

“…The microelectrodes fabricated by this research team feature a wrinkled surface morphology, which allows for a fast response time to be achieved. Chmayssem et al integrated a cell culture chamber with electrochemical impedance spectroscopy, as shown in Figure 3d [48]. The researchers used a screen-printing technique to fabricate the microelectrodes on polyethylene terephthalate (PET) sheets.…”

“…(d) Microelectrodes were microfabricated on polyethylene terephthalate (PET) sheets. Reproduced with permission from [48]. Copyright Biosensors 2022.…”

Vat photopolymerization 3D printed microfluidic devices for organ-on-a-chip applications

“…143 To date, the most commonly reported strategies involve patterning electrodes on a glass capping substrate, which is used to seal the microfluidic devices. 143,144 This process involves screen printing 145 and/or vapor deposition 146 of electrodes on the glass substrate. Since 3D printed resins cannot be readily bonded to the electrode-patterned glass substrates, researchers will require alternate methods of incorporating electrodes into 3D printed OoCs.…”