Graphene Microelectrodes for Real-Time Impedance Spectroscopy of Neural Cells

Abstract

Understanding the changes in the electrochemical properties of neural cells upon exposure to stress factors imparts vital information about the conditions prior to their death. This study presents a graphene-based biosensor for real-time monitoring of N27 rat dopaminergic neural cells which characterizes cell adhesion and cytotoxicity factors through impedance spectroscopy. The aim was to monitor the growth of the entire cell network via a nonmetallic flexible electrode array. Therefore, a water-based graphene solution was formulized as a conductive ink, 3D-printed into a flexible substrate through an electrohydrodynamic approach, resulting in electrodes with a conductivity of 6750 s/m. The presented high-throughput method enabled microscale monitoring of the entire cell network via the design of PDMS-based growth channels. The electrical resistance of the cell network was measured continuously along with their network density, constituting a mean density of 1890 cell/mm2 at full cell confluency. The results demonstrate the applicability of the impedance-based sensing of the cell network for rapid screening of the cytotoxic elements, and the real-time effect of UV exposure on dopaminergic neural cells was reported as an immediate application of the device.

Hydrodynamic Assembly of Astrocyte Cells in Conductive Hollow Microfibers

“…[23,31,[36][37][38][39][40] Recently, the induction of electrical properties to hydrogel structures by conductive biocompatible modifiers such as graphene, graphene oxide, reduced graphene oxide, and synthetic polymers such as polypyrrole or poly (3,4ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) have been investigated by a number of studies to elucidate electrical cell-to-cell communication mechanisms within neuronal cell cultures. [13,[41][42][43][44][45][46][47][48][49][50] With the recent use of conductive biocompatible modifiers, alginate 3D microstructures have the potential to be further improved to accommodate the use of electrical stimulation on specific cell cultures and experiments. Specifically, the implementation of conductive biocompatible modifiers to alginate 3D microstructures may lead to more accurate and elaborate neuronal cell cultures where electrical stimuli are much more prevalent.…”