Spectroelectrochemical characterization of ultrathin organic films deposited on electrode surfaces
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: Casanova Moreno, Jannu Ricardo
issued: 2014-12-31T08:00:00Z
issued: 2014
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Thin organic layers deposited on electrodes are ubiquitously proposed for a variety of surface-related applications. The quality of these layers is usually assessed by analytical methods that average the measured signal over a large area compared to the molecular scale. This work outlines the use of in-situ fluorescence microscopy as a characterization method by analyzing three examples of such layers. First, a heterogeneous Langmuir layer was physically adsorbed to a gold electrode via the Langmuir-Schaefer method and the effects of the substrate analyzed by comparing the adsorbed layer with the predecessor floating film. Through the use of a dimer-forming fluorophore, substrate mediated condensation was suggested. Second, the reductive desorption of self-assembled monolayers (SAMs) from microelectrodes was used to investigate the movement of the released thiolate molecules. Once in solution, these molecules were found to follow a buoyant movement, consequence of the high local concentration of H₂ resulting from the simultaneous reduction of water under the conditions employed. Finally, a DNA SAM system that has been previously suggested as a biosensing platform was investigated for heterogeneity. It was found that the substrate crystallography had a significant effect on the density and efficiency of potential driven change in conformation of the immobilized probes. Furthermore, a deconvolution method is proposed in order to correct for the effect of the electrode charging time constant on the measurements of the kinetics of the DNA conformation change. Overall, the performed experiments show that in-situ fluorescence microscopy is a useful technique to analyze distance dependent phenomena involving these deposited layers. Moreover, the coupling between electrochemistry and fluorescence allows not only to monitor but also to drive changes in the layers, creating systems capable of studying the dynamics of the deposited films. The inclusion of the proposed techniqu…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/47073
note: SpectroelectrochemicalCharacterization of Ultrathin OrganicFilms Deposited on Electrode SurfacesbyJannu Ricardo Casanova MorenoB.Sc., Universidad Nacional Autonoma de Mexico, 2006A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinThe Faculty of Graduate and Postdoctoral Studies(Chemistry)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)June 2014© Jannu Ricardo Casanova Moreno 2014AbstractThin organic layers deposited on electrodes are ubiquitously proposed for a variety of surface-relatedapplications. The quality of these layers is usually assessed by analytical methods that average themeasured signal over a large area compared to the molecular scale. This work outlines the use of in-situ fluorescence microscopy as a characterization method by analyzing three examples of such layers.First, a heterogeneous Langmuir layer was physically adsorbed to a gold electrode via the Langmuir-Schaefer method and the effects of the substrate analyzed by comparing the adsorbed layer with thepredecessor floating film. Through the use of a dimer-forming fluorophore, substrate mediated conden-sation was suggested.Second, the reductive desorption of self-assembled monolayers (SAMs) from microelectrodes wasused to investigate the movement of the released thiolate molecules. Once in solution, these moleculeswere found to follow a buoyant movement, consequence of the high local concentration of H2 resultingfrom the simultaneous reduction of water under the conditions employed.Finally, a DNA SAM system that has been previously suggested as a biosensing platform was in-vestigated for heterogeneity. It was found that the substrate crystallography had a significant effect onthe density and efficiency of potential driven change in conformation of the immobilized probes. Fur-thermore, a deconvolution method is proposed in order to correct for the effect of the electrode chargingtime constant on the measurements of the kinetics of the DNA conformatio…
has type: Thesis/Dissertation
date issued: 2014-09
is shown at: 10.14288/1.0167244
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial 2.5 Canada
rights URI: http://creativecommons.org/licenses/by-nc/2.5/ca/
scholar level: Graduate
type: Text
type: Moving Image
identifier URI: http://hdl.handle.net/2429/47073