Berlin 2005 – scientific programme

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HL: Halbleiterphysik

HL 48: Symposium: Bio- and Neurotransistors

HL 48.5: Talk

Tuesday, March 8, 2005, 12:45–13:15, TU P270

Biosensor Applications of AlGaN/GaN Solution Gate Field Effect Transistors — •Georg Steinhoff, Barbara Baur, Martin Stutzmann, and Martin Eickhoff — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching

AlGaN surfaces are chemically inert in aqueous solutions and non-toxic to living cells. Covalent functionalization with self assembled monolayers (SAMs) of APTES for the immobilization of single stranded oligonucleotides and of ODTMS for the subsequent deposition of lipid monolayers is possible, allowing label-free detection of DNA hybridization or the detection of ligand binding to specific receptors in lipid monolayers on functionalized gates of solution gate AlGaN/GaN heterostructure field effect transistors. A different approach for the realization of biosensors is the cultivation of living cells directly on the gate area and the measurement of their ionic response to chemical or physical stimuli. We systematically studied the electronic characteristics of AlGaN/GaN FET arrays for the detection of electrical cell signals, such as low-frequency noise, transconductance and the sensitivity towards specific ions. Extracellular action potential recordings from a confluent layer of rat heart muscle cells cultivated directly on the non-metallized gate surface are discussed.