Mass transport at rotating disk electrodes: effects of synthetic particles and nerve endings.

Autor: Chiu VM; Department of Chemistry, Washington State University, Pullman, WA 99164, USA., Lukus PA, Doyle JL, Schenk JO
Jazyk: angličtina
Zdroj: Analytical biochemistry [Anal Biochem] 2011 Nov 01; Vol. 418 (1), pp. 58-65. Date of Electronic Publication: 2011 Jul 13.
DOI: 10.1016/j.ab.2011.07.003
Abstrakt: An unstirred layer (USL) exists at the interface of solids with solutions. Thus, the particles in brain tissue preparations possess a USL as well as at the surface of a rotating disk electrode (RDE) used to measure chemical fluxes. Time constraints for observing biological kinetics based on estimated thicknesses of USLs at the membrane surface in real samples of nerve endings were estimated. Liposomes, silica, and Sephadex were used separately to model the tissue preparation particles. Within a solution stirred by the RDE, both diffusion and hydrodynamic boundary layers are formed. It was observed that the number and size of particles decreased the following: the apparent diffusion coefficient excluding Sephadex, boundary layer thicknesses excluding silica, sensitivity excluding diluted liposomes (in agreement with results from other laboratories), limiting current potentially due to an increase in the path distance, and mixing time. They have no effect on the detection limit (6 ± 2 nM). The RDE kinetically resolves transmembrane transport with a timing of approximately 30 ms.
(Copyright © 2011 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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