title: Ion-selective detection by plasticized poly(vinyl chloride) membrane in glass nanopipette with alternating voltage modulation.
abstract: An alternating current (AC) voltage modulation was applied to ion-selective observations with plasticized poly(vinyl chloride) membranes in glass nanopipettes. The liquid confronting the membranes in the nanopipettes, the conditioning process, and AC voltage modulation play important roles in the ion-selective detection. In the AC detection system developed by us, where distilled water was used as the liquid within the nanopipettes, potassium ions were selectively detected in the sample solution of sodium and potassium ions because sodium ions were captured at the membrane containing bis(12-crown-4) ionophores, before the saturation of the ionophores. The membrane lost the selectivity after the saturation. On using sodium chloride as the liquid within the nanopipette, the membrane selectively detected potassium and sodium ions before and after the saturation of ionophores, respectively. The ion-selective detection of our system can be explained by the ion extraction-diffusion-dissolution mechanism through the bis(12-crown-4) ionophores with AC voltage modulation.
authors.affiliation: Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Xiao Long
authors.initials: XL
authors.lastname: Deng
authors.forename: Tomohide
authors.initials: T
authors.lastname: Takami
authors.forename: Jong Wan
authors.initials: JW
authors.lastname: Son
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Kang
authors.forename: Tomoji
authors.initials: T
authors.lastname: Kawai
authors.forename: Bae Ho
authors.initials: BH
authors.lastname: Park