title: A gold-gold oil microtrench electrode for liquid-liquid anion transfer voltammetry.
abstract: Two flat gold electrodes are placed vis-à-vis with an epoxy spacer layer that is etched out to give a ca. 100 μm-deep electrochemically active trench. A water-insoluble oil phase, here the redox system N,N-diethyl-N'N'-didodecyl-phenylenediamine (DDPD) in 4-(3-phenylpropyl)-pyridine (PPP), is immobilized into the trench to allow anion transfer upon oxidation of DDPD (oil) to DDP⁺ (oil). In "mono-potentiostatic mode" quantitative transfer/expulsion of anions into the trench oil phase occurs. However, in "bi-potentiostatic mode" feedback currents dominated by rapid plate-to-plate diffusion normal to the electrode surfaces are observed. Comparison of "normal" diffusion and "lateral" diffusion shows that the rate of diffusion-migration charge transport across the oil film is anion hydrophobicity dependent.
authors.affiliation: Department of Chemistry, University of Bath, Bath, UK.
authors.forename: Sara E C
authors.initials: SE
authors.lastname: Dale
authors.forename: Yohan
authors.initials: Y
authors.lastname: Chan
authors.forename: Philip C
authors.initials: PC
authors.lastname: Bulman Page
authors.forename: Edward O
authors.initials: EO
authors.lastname: Barnes
authors.forename: Richard G
authors.initials: RG
authors.lastname: Compton
authors.forename: Frank
authors.initials: F
authors.lastname: Marken
mesh_terms: D000838:Anions / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D009821:Oils / Q000737:chemistry*; D010084:Oxidation-Reduction; D010655:Phenylenediamines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D000838:Anions; D009821:Oils; D010655:Phenylenediamines; D011725:Pyridines; D006046:Gold
keywords: Analysis; Ion transfer; Junction; Liquid-liquid interface; Sensor