Electro-Optics of Unilamellar Vesicles

Electric field-induced transient birefringence and light scattering are reported for aqueous suspensions of synthetic unilamellar bilayer vesicles, prepared from the lipid dioleoylphosphatidylcholine (DOPC). The multiexponential birefringence relaxations observed on the microsecond and millisecond timescales are interpreted in terms of elongation and reorientation of induced dipolar vesicles, their linear chain formation, and electrofusion (and possibly electroporation) of the vesicles. Above certain threshold values of vesicle concentration, field-induced light scattering occurs concomitant with the birefringence. The corresponding transient signals corroborate the linear chain formation and subsequent fusion of the induced dipolar vesicles.