title: SoI--gel modification of pH electrode glass membranes for sensing anions and metal ions.
abstract: To obtain glass membrane electrodes selective for anions and metal ions, pH electrode glass membranes were modified by a sol-gel method using a quaternary ammonium salt and a bis(crown ether). A chloride ion-sensing glass membrane was designed, in which a pH electrode glass membrane was modified chemically by an alkoxysilyl quaternary ammonium chloride. X-ray photoelectron spectroscopy confirmed the chemical bonding of the quaternary ammonium moiety to the starting glass surface, which afforded the first example of glass-based "anion"-sensing membranes. A neutral carrier-type sodium ion-selective glass membrane was also fabricated which encapsulates a bis(12-crown-4) derivative in its sol-gel-derived surface. Both sol-gel-modified anion and metal ion-selective glass electrodes exhibited high sensitivity to their ion activity changes. The present sol-gel modification paves the way for designing glass-based ion sensors with tailor-made ion selectivities toward anions as well as cations.
authors.affiliation: Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, Japan. kimura@sys.wakayama-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: S
authors.initials: S
authors.lastname: Yajima
authors.forename: H
authors.initials: H
authors.lastname: Takase
authors.forename: M
authors.initials: M
authors.lastname: Yokoyama
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai