Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 85: Organic Semiconductors: Transistors and OLEDS

HL 85.5: Talk

Thursday, March 29, 2012, 16:00–16:15, EW 203

Bio-functionalization of electrolyte-gated organic transistors — •Felix Buth, Andreas Donner, Aiswarya Pillai, Martin Stutzmann, and Jose Antonio Garrido — Walter Schottky Institut, Technische Universität München, Garching, Germany

Electrolyte-gated organic field-effect transistors (EGOFETs) can be operated at low voltages in aqueous environments, paving the way to the use of organic semiconductors in bio-sensing applications. However, it has been shown that these devices exhibit inherently a rather weak sensitivity to relevant electrolyte parameters such as pH and ionic strength. In order to increase this sensitivity and add specificity towards a given analyte, the covalent attachment of functional groups to the device surface would be desirable.

In this contribution we demonstrate the successful attachment of different silane molecules, which serve as linker molecules for the subsequent grafting of bio-molecules, to the surface of α-sexithiophene-based thin film transistors. Using surface characterization techniques like X-ray photoemission and infra-red spectroscopy we could confirm the presence of functional groups on the surface, which are stable under standard electrolytic conditions. As expected, the presence of these amphoteric groups (e.g. amino or carboxylic moieties) increases the pH-sensitivity of the EGOFETs. In addition, they can serve as anchoring sites for further bio-functionalization steps. These results confirm the potential of the EGOFETs for chemical- or biochemical-sensing applications.