Investigation of electrostatic interactions in polyelectrolyte multilayer films: Binding of anionic fluorescent probes to layers assembled onto colloids

Abstract

The electrostatic binding of two anionic probe molecules, pyrenetetrasulfonic acid (4-PSA) and 6-carboxyfluorescein (6-CF), to poly(allylamine hydrochloride) (PAH)/poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC)/PSS ultrathin multilayer films assembled onto polystyrene (PS) latex particles has been examined using fluorescence spectroscopy. At the probe concentrations studied, binding was observed only when the outermost layer was oppositely (positively) charged to the probe. The amount of probe bound was found to increase linearly with polyelectrolyte layer number up to about 11 layers (15 nm in thickness for the PAH/PSS films), with saturation bind..