3.5.1 Selective ion sensors based on ionophore-modified graphene field-effect transistors

Event
14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany
Chapter
3.5 ISFETs
Author(s)
K. Maehashi, Y. Sofue, S. Okamoto, Y. Ohno, K. Inoue, K. Matsmoto - The Institute of Scientific and Industrial Research, Osaka University (Japan)
Pages
305 - 308
DOI
10.5162/IMCS2012/3.5.1
ISBN
978-3-9813484-2-2
Price
free

Abstract

Selective potassium (K) ion sensors were fabricated by modifying graphene field-effect transistors (FETs) with valinomycin, a selective K ionophore. The valinomycin-modified graphene FETs demonstrated highly sensitive, selective electrical detection of K ions in electrolytes. The K ions bound to the valinomycin in the graphene channel and affected the electrical potential of the channel. The transfer curves were shifted in a negative direction as the K ion concentration increased, indicating that K ions in solution were effectively detected over a wide concentration range, from 10 nM to 1.0 mM. The addition of Na ions did not cause any change in the transfer characteristics. We have thus demonstrated the utility of graphene FETs as highly sensitive, selective K ion sensors.

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