title: Electrolyte-gated graphene field-effect transistors for detecting pH and protein adsorption.
abstract: We investigated electrolyte-gated graphene field-effect transistors (GFETs) for electrical detecting pH and protein adsorptions. Nonfunctionalized single-layer graphene was used as a channel. GFETs immersed in an electrolyte showed transconductances 30 times higher than those in a vacuum and their conductances exhibited a direct linear increase with electrolyte pH, indicating their potential for use in pH sensor applications. We also attempted to direct surface-protein adsorption and showed that the conductance of GFETs increased with exposure to a protein at several hundred picomolar. The GFETs thus acted as highly sensitive electrical sensors for detecting pH and biomolecule concentrations.
authors.affiliation: The Institute of the Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan. ohno@sanken.osaka-u.ac.jp
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Ohno
authors.forename: Kenzo
authors.initials: K
authors.lastname: Maehashi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamashiro
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D025802:Electric Capacitance; D004553:Electric Conductivity; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004573:Electrolytes; D012710:Serum Albumin, Bovine; D006108:Graphite