AlGaN/GaN Electrolyte-Gate Field-Effect Transistors as Transducers for Bioelectronic Devices

Abstract

AlGaN/GaN electrolyte gate field-effect transistors are assessed as a transducer device for biosensor applications. Their low-frequency noise power spectral density 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 15 μ V, one order of magnitude smaller than for common silicon-based devices. The untreated GaN device surface showed a high linear pH response of 56 – 57 mV/pH, whereas the sensitivity to other ions is comparably low. Arrays of these transistors have been used for monitoring of action potentials from a confluent layer of rat heart muscle cells cultivated directly on the non-metallized gate surfaces and signals with an amplitude of 1.2 mV were recorded.