Enzyme-modified electrolyte-gated organic field effect transistors

Felix Buth, Andreas Donner, Martin Stutzmann, Jose A. Garrido

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

3 Scopus citations


Organic solution-gated field-effect transistors (SGFETs) 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 only a rather weak sensitivity to standard electrolyte parameters such as pH and ionic strength. In order to increase the sensitivity and to add specificity towards a given analyte, the covalent attachment of functional groups and enzymes to the device surface would be desirable. In this contribution we demonstrate that enzyme modified organic SGFETs can be used for the in-situ detection of penicillin in the low M regime. In a first step, silane molecules with amine terminal groups are grafted to sexithiophene-based thin film transistors. Surface characterization techniques like X-ray photoemission confirm the modification of the surface with these functional groups, which are stable in standard aqueous electrolytes. We show that the presence of surface-bound amphoteric groups (e.g. amino or carboxylic moieties) increases the pH-sensitivity of the organic SGFETs. In addition, these groups serve as anchoring sites for the attachment of the enzyme penicillinase. The resulting enzyme-FETs are used for the detection of penicillin, enabling the study of the influence of the buffer strength and the pH of the electrolyte on the enzyme kinetics. The functionalization of the organic FETs shown here can be extended to a large variety of enzymes, allowing the specific detection of different chemical and biochemical analytes.

Original languageEnglish
Title of host publicationOrganic Semiconductors in Sensors and Bioelectronics V
StatePublished - 2012
EventOrganic Semiconductors in Sensors and Bioelectronics V - San Diego, CA, United States
Duration: 15 Aug 201216 Aug 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceOrganic Semiconductors in Sensors and Bioelectronics V
Country/TerritoryUnited States
CitySan Diego, CA


  • (Organic) Field-Effect Transistors
  • Bioelectronics
  • Enzymes
  • Organic Electronics
  • Sensors/Biosensors


Dive into the research topics of 'Enzyme-modified electrolyte-gated organic field effect transistors'. Together they form a unique fingerprint.

Cite this