title: Potassium selective chemically modified field effect transistors based on AlGaN/GaN two-dimensional electron gas heterostructures.
abstract: We investigate the use of the AlGaN/GaN high electron mobility transistor (HEMT) as a novel transducer for the development of ion-selective chemically modified HEMT sensors (ChemHEMTs). For this, polyvinyl chloride (PVC) membrane doped with ion-selective ionophores is deposited onto the area of the gate for the chemical recognition step, while the AlGaN/GaN HEMT is used as the transducer. In particular, the use of a valinocycin doped membrane with thickness of 50 microm generates a sensor with excellent analytical characteristics for the monitoring of K(+). The K(+)-ChemHEMT has sensitivity of 52.4 mV/pK(+)in the linear range of 10(-5) to 10(-2)M, while the detection limit is in the order of 3.1 x 10(-6)M. Also, the sensor shows selectivity similar to valinomycin-based ISEs, while the signal stability over time and the measurement to measurement reproducibility are very good.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Crete, Voutes, PO Box 2208, 71003 Iraklion-Crete, Greece.
authors.forename: Y
authors.initials: Y
authors.lastname: Alifragis
authors.forename: A
authors.initials: A
authors.lastname: Volosirakis
authors.forename: N A
authors.initials: NA
authors.lastname: Chaniotakis
authors.forename: G
authors.initials: G
authors.lastname: Konstantinidis
authors.forename: A
authors.initials: A
authors.lastname: Adikimenakis
authors.forename: A
authors.initials: A
authors.lastname: Georgakilas
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004583:Electrons; D005708:Gallium / Q000737:chemistry*; D011188:Potassium / Q000032:analysis*; D011199:Potentiometry; D014173:Transistors, Electronic
chemical_list: D017607:Aluminum Compounds; C513700:aluminum gallium nitride; C473348:gallium nitride; D005708:Gallium; D011188:Potassium