Solution-Gated Epitaxial Graphene as pH Sensor
- 14 October 2008
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 130 (44), 14392-14393
- https://doi.org/10.1021/ja805090z
Abstract
A solution-gate field effect transistor (SGFET) has been fabricated on few-layer graphene (FLG). The ideally polarizable graphene/aqueous electrolyte interface allows the capacitive charging of the surface by hydroxyl (OH−) and hydroxonium ions (H3O+). The conductivity versus gate potential curve exhibits “V” shaped ambipolar transfer characteristics of graphene, with hole and electron mobilities of 3600 cm2/Vs and 2100 cm2/Vs, respectively. The shift of the negative gate potential with pH shows a supra-Nernstian response of 99 meV/pH. Our work points to the potential application of graphene in ultrafast and ultralow noise chemical or biological sensors.Keywords
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