Use of 9-aminoacridine in the evaluation of liposome surface charge density: Role of the adsorption on lipidic sites (original) (raw)

The procedure of surface charge density evaluation using 9-aminoacridine as a fluorescent probe implies that cations do not interact with the negatively charged lipids. From surface potential measurements on lipid monolayers coupled with fluorescence measurements on liposomes, we demonstrate that the cations present in the aqueous phase, including the fluorescent probe itself, interact with the lipidic sites. These association reactions should not be neglected in the evaluation of the surface charge density associated with mode1 membranes. l Contribution presented at the VIIIth International Symposium on Bioelectrochemistry and Biocnergetits, Bologna, June 24th-29th 1985.