title: Needle-type ultra micro silver/silver chloride reference electrode for use in micro-electrochemistry.
abstract: A needle-type ultra micro silver/silver chloride reference electrode having a micro capillary with outer and inner diameters of 1.0 microm and 0.5 +/- 0.2 microm, respectively, was constructed. This micro reference electrode can be stuck into a living cell, and is applicable to use in very small environments, such as an electrochemical cell of an electrochemical scanning tunneling microscope or the detection portion of a micro-TAS. Excellent stability and repeatability of the micro reference electrode potential could be obtained by filling the micro capillary with agar gel containing 3.33 mol/L potassium chloride as a salt bridge, by covering the bare part of the silver wire on which silver chloride was deposited, and by electromagnetic shielding of the measurement cell and wire lead from the electromagnetic waves. The electrode showed stable potential for 7 days after its fabrication using 3.3 mol/L potassium chloride aqueous solution containing silver chloride as an internal electrolyte solution. The electrode exhibited constant electrode potential and excellent stability in test solutions of pH 5-9. The electrode potential of a commercial pH glass electrode measured against the micro reference electrode in standard pH buffer solutions was in good accordance with the Nernst equation.
authors.affiliation: Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan. kitade@mb.kyoto-phu.ac.jp
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kitade
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kitamura
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Takegami
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miyata
authors.forename: Miwa
authors.initials: M
authors.lastname: Nagatomo
authors.forename: Tomomi
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Michiko
authors.initials: M
authors.lastname: Furukawa
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation*; D008839:Microelectrodes; D012834:Silver / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry*
chemical_list: D018030:Silver Compounds; D012834:Silver; C037548:silver chloride