Nerve cell response to inhibitors recorded with an aluminum–galliumnitride/galliumnitride field-effect transistor

Experiments based on neuronal cell–transistor couplings were made from some groups during the last years. Pioneering work in this field was carried out by Fromherz and his group (Fromherz, 2003 and Schmidtner and Fromherz, 2006). We were interested of the interaction of nerve cells to serine hydrolase inhibitor diisopropylfluorophosphate (DFP), monitored by using an aluminum–galliumnitride/galliumnitride (AlGaN/GaN) electrolyte gate field effect transistor (EGFET). The biocompatibility study of our sensor materials with nerve cells shows a proliferation rate of at least 95%. The inhibitors were added to the medium and the source-drain current of the EGFET was recorded as a function of time. The inhibitor was added to the NG108-15 nerve cells growing directly on the sensor surface, resulting in a fast decrease in the drain current, IDS. Control measurements show that this response is associated with cationic fluxes pumped through ionic channels present in the cellular membrane. The sensor enables analysis of the ion channel activity without cell destruction and simultaneously allows visual observation due to the optical transparency of the sensor material.

► Label-free detection of sodium flux in cellular channel proteins.
► Non-destructive measurement of channel activity in neuronal cells.
► Preparation and use of AlGaN/GaN electrolyte gate field effect transistors as cell culture compatible measurement device.
► Measurement of sodium concentration changes with AlGaN/GaN electrolyte gate field effect transistors.