Quantitative visualization of molecular transport through porous membranes : enhanced resolution and contrast using intermittent contact-scanning electrochemical microscopy
McKelvey, Kim, Snowden, Michael E., Peruffo, Massimo and Unwin, Patrick R.. (2011) Quantitative visualization of molecular transport through porous membranes : enhanced resolution and contrast using intermittent contact-scanning electrochemical microscopy. Analytical Chemistry, Vol.83 (No.17). pp. 6447-6454. ISSN 0003-2700Full text not available from this repository.
Official URL: http://dx.doi.org/10.1021/ac201489c
The use of intermittent contact-scanning electrochemical microscopy (IC-SECM) in diffusion-limited amperometric mode to visualize and quantify mass transport through multiporous membranes is described using dentin as a model example. The IC mode of SECM employs the damping of a vertically modulated ultramicroelectrode (UME) to achieve positioning close to the receptor side of a membrane. In this way the UME can detect electroactive species close to the pore exit. A key aspect of IC-SECM is that in addition to the direct current (dc) from the diffusion-limited detection of the analyte, an alternating current (ac) also develops due to the motion of the probe. It demonstrates that this ac signal enhances the spatial resolution of SECM detection and allows the hydrodynamic flow of species to be detected from individual closely spaced pores. The experimental deductions are supported by three-dimensional finite element modeling which allows IC-SECM current maps to be analyzed to reveal transport rates through individual pores. The method described should be widely applicable to multiporous membrane transport.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QH Natural history > QH301 Biology
|Divisions:||Faculty of Science > Chemistry|
|Library of Congress Subject Headings (LCSH):||Electrochemistry, Bilayer lipid membranes, Atomic force microscopy, Scanning electrochemical microscopy, Porous materials, Membranes (Biology) -- Fluidity, Nanostructured materials|
|Journal or Publication Title:||Analytical Chemistry|
|Publisher:||American Chemical Society|
|Page Range:||pp. 6447-6454|
|Funder:||Engineering and Physical Sciences Research Council (EPSRC), Advantage West Midlands (AWM), European Regional Development Fund (ERDF)|
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