title: All-solid-state potassium-selective electrode using graphene as the solid contact.
abstract: Graphene sheets are used for the first time to fabricate a new type of solid-contact ion-selective electrode (SC-ISE) as the intermediate layer between an ionophore-doped solvent polymeric membrane and a glassy carbon electrode. The new transducing layer was characterized by transmission electron microscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The performance of the new K(+-)selective electrodes was examined by a potentiometric water layer test, potentiometric measurements, and current reversal chronopotentiometry. The obtained potentiometric sensors were characterized with a calibration line of slope close to Nernstian (59.2 mV/decade) within the activity from 10(-4.5) to 0.1 M. The high capacitance of the graphene solid contacts results in a signal that is stable over one week. The short response time is less than 10 s for activities higher than 10(-5) M. The potential drift of the electrodes was calculated from the slope of the curves at longer times (ΔE/Δt = 1.2 × 10(-5) V s(-1) (I = 1 nA) and ΔE/Δt = 5.5 × 10(-5) V s(-1) (I = 5 nA)). All the results indicate that graphene is a promising material for use as a transducer layer for SC-ISEs.
authors.affiliation: Engineering Laboratory for Modern Analytical Techniques, Changchun Institute of Applied Chemistry, and Graduate University of the Chinese Academy of Sciences, Chinese Academy of Sciences, Changchun, 130022, PR China.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Li
authors.forename: Junjin
authors.initials: J
authors.lastname: Ye
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.forename: Shiyu
authors.initials: S
authors.lastname: Gan
authors.forename: Qixian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Dongxue
authors.initials: D
authors.lastname: Han
authors.forename: Li
authors.initials: L
authors.lastname: Niu