Spectrofluorimetric Characterization of Mixed Nanoaggregates Comprising a Double-Chain Cationic Surfactant and a Cationic or Non-Ionic Single-Chain Surfactant

Abstract

A series of mixed vesicle and pre-vesicle nanoaggregates, comprising a cationic double-chain surfactant (di-decyldimethylammonium bromide, di-C10DMAB, or di-dodecyldimethylammonium bromide, di-C12DMAB), and a cationic (dodecylethyldimethylammonium bromide, C12EDMAB) or non-ionic (octyl-β-D-glucopyranoside, OBG) single-chain surfactant have been characterized by means of steady-state fluorescence spectroscopy. For that purpose, the fluorescent emission of two probes, one anionic (TNS) and the other non-ionic (PRODAN), which is known to be sensitive to the polarity, rigidity, and/or microviscosity of the environment within which the probes are housed, has been measured in the presence of the above-mentioned mixed aggregates. The results of this analysis yield interesting information about the characteristics of the vesicle surface and bilayer, as well as about the existence of clusters and/or nanoaggregates prior to the formation of vesicles.