title: Crown-Ether Derived Graphene Hybrid Composite for Membrane-Free Potentiometric Sensing of Alkali Metal Ions.
abstract: We report the design and synthesis of newly functionalized graphene hybrid material that can be used for selective membrane-free potentiometric detection of alkali metal ions, represented by potassium ions. Reduced graphene oxide (RGO) functionalized covalently by 18-crown[6] ether with a dense surface coverage is achieved by the introduction of a flexible linking molecule. The resulting hybrid composite is highly stable and is capable of detecting potassium ions down to micromolar ranges with a selectivity over other cations (including Ca(2+), Li(+), Na(+), NH4(+)) at concentrations up to 25 mM. This material can be combined further with disposable chips, demonstrating its promise as an effective ion-selective sensing component for practical applications.
authors.affiliation: Department of Chemistry, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Olsen
authors.affiliation: Department of Chemistry, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Ulstrup
authors.affiliation: Department of Chemistry, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
authors.forename: Qijin
authors.initials: Q
authors.lastname: Chi
keywords: chemical sensor; crown ether; disposable electrode; hybrid material; potassium ions; reduced graphene oxide