Characterization of mixed alcohol monolayers adsorbed onto a Au(111) electrode using electro-fluorescence microscopy

A single-crystal Au(111) electrode modified with an adsorbed layer of 1-octadecanol (C18OH) or oleyl alcohol (OLA) in pure or mixed composition was characterized using electrochemical and in situ fluorescence microscopy. Cyclic voltammetry and differential capacitance measurements revealed a repeata...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 22(2006), 10 vom: 09. Mai, Seite 4869-76
1. Verfasser: Shepherd, Jeff L (VerfasserIn)
Weitere Verfasser: Bizzotto, Dan
Format: Aufsatz
Sprache:English
Veröffentlicht: 2006
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Fatty Alcohols Fluorescent Dyes oleyl alcohol 172F2WN8DV stearyl alcohol 2KR89I4H1Y Gold 7440-57-5
Beschreibung
Zusammenfassung:A single-crystal Au(111) electrode modified with an adsorbed layer of 1-octadecanol (C18OH) or oleyl alcohol (OLA) in pure or mixed composition was characterized using electrochemical and in situ fluorescence microscopy. Cyclic voltammetry and differential capacitance measurements revealed a repeatable, potential-induced adsorption/desorption process of the surfactant to/from the electrode surface while charge density and film pressure measurements indicated quasi-ideal mixing of the two adsorbed alcohols. A layer less defective than pure C18OH was created with incorporated OLA. Optical characterization was accomplished using epi-fluorescence microscopy combined with electrochemistry (electro-fluorescence microscopy) through the incorporation of two fluorescent probes into the adsorbed surfactant layer. Since molecular luminescence is quenched by a nearby metal, fluorescence was only observed when the fluorescent dye/alcohol layers were desorbed and therefore separated from the metal surface. When desorbed, the structure of the alcohol layers were similar in character, revealing aggregated features which did not change in morphology over numerous desorption/re-adsorption cycles. We have also used the electro-fluorescence technique to estimate the distance separating the metal and desorbed surfactant and believe that the molecules are displaced from the electrode surface by a distance not more than 40 nm
Beschreibung:Date Completed 03.08.2007
Date Revised 15.11.2012
published: Print
Citation Status MEDLINE
ISSN:1520-5827