Zajednički kolokvij Zavoda za istraživanje mora i okoliša i Hrvatskog biofizičkog društva

Sažetak:This talk describes the use of electrochemical impedance spectroscopy to understand the behaviour of phospholipid layers on mercury electrodes as a function of potential and when interacting with biologically-active peptides in solution.

Experiments were carried out using frequencies between 0.1 and 65000 Herz on coated and uncoated electrodes. The results clarify the properties of the phospholipid layers at different values of the applied field and they help to characterise three consecutive phase transitions. Interactions with gramicidin peptides are quantitative and selective. A general one and two capacitor model has been developed and applied which takes account of frequency dispersion in the capacitor and interfacial problems between the capacitor and the solution resistance.