Spontaneous electrical potential oscillation on a filter impregnated with soybean lecithin placed between identical solutions of alanine Original Research Article

Filters impregnated with soybean lecithin, placed between two identical aqueous alanine solutions, display spontaneous electric potential oscillations. Alanine solutions used in a large concentration range from 1 mM to 1 M produce damped oscillatory behaviour with an exponential decay in time. The dependence of decay time on concentration shows saturation behaviour which is well fitted with a sigmoidal curve. Power spectra obtained by Fourier transform show peaks specific for each concentration. When fitted with a Lorentzian curve in the peak domain, the centre of the peak height and width at half height could be extracted. All these parameters depend on alanine concentration in a saturating pattern.