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Conducting polymers as model biological membranes
Abo Akademi University, Center for Process Analytical Chemistry and Sensor Technology ProSens (PROSENS), Biskopsgatan 8, Turku 00410, Finland
Conducting polymers (CPs) films, poly(3,4-ethylene- dioxythiophene) (PEDOT) and poly(pyrrole), doped with adenosine triphosphate, heparin, asparagine or glutamine and made sensitive to calcium and magnesium are used to study the influence of a competitive magnesium and calcium ion-exchange on a membrane potential formation.
The films are analyzed by X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive Analysis of X-rays (EDAX) to show how their topography and morphology is influenced by the conditions during electrodeposition and post-deposition soaking. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) are used to prove that the topography and morphology of the films determines the quality of their open-circuit (potentiometric) response. More smooth and less rough films result in better potentiometric characteristics, particularly in a faster response, which is a prerequisite for using the CPs films as model biological membranes.
Membrane potential transients provoked by a competitive calcium and magnesium ion-exchange at the sites (dopants) dispersed in the films, and the mechanism of activation of calcium channels blocked by magnesium-site interaction are investigated. Theoretical interpretation in time domain is obtained by the numerical resolution of Nernst-Planck-Poisson (NPP) coupled equations or simpler diffusion-layer model, deduced from the NPP.
Presentation: Tutorial lecture at SMCBS'2005 Workshop, by Andrzej Lewenstam
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-07-20 10:57 Revised: 2009-06-07 00:44