Organic field-effect transistor-based biosensors functionalized with protein receptors

Francesco Maddalena*, Marjon J. Kuiper, Bert Poolman, Frank Brouwer, Jan C. Hummelen, Dago M. de Leeuw, Bert de Boer, Paul W. M. Blom

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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An organic field-effect transistor with integrated proteins (Bio-FET) for sensing of sulfate ions is presented. A sulfate receptor was engineered to contain a thiol group for surface-anchoring without affecting its binding activity. The modified receptor was covalently coupled to a maleimide-functionalized polystyrene layer, and integrated as gate dielectric in a dual-gate transducer. The binding of sulfate ions in dry conditions was detected by a shift in the threshold voltage. Combined with surface density measurements by atomic force microscopy , an effective charge of −1.7q per protein was found, as expected from the Bio-FET operation model.
Original languageEnglish
Article number124501
Pages (from-to)124501-1-124501-4
Number of pages4
JournalJournal of Applied Physics
Issue number12
Publication statusPublished - 15-Dec-2010



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