Recording of cell action potentials with AlGaN∕GaN field-effect transistors

An AlGaN∕GaN electrolyte gate field-effect transistor array for the detection of electrical cell signals has been realized. The low-frequency noise power spectral density of these devices exhibits a 1∕f characteristic with a dimensionless Hooge parameter of 5×10−3. The equivalent gate-input noise under operation conditions has a peak-to-peak amplitude of 15μV, one order of magnitude smaller than for common silicon-based devices used for extracellular recordings. Extracellular action potentials from a confluent layer of rat heart muscle cells cultivated directly on the nonmetallized gate surface were recorded with a signal amplitude of 75μV and a signal-to-noise ratio of 5:1.