Effect of triazine dye on electrical conductivity and extraction of bovine serum albumin in reversed micelles formed with cetyltrimethylammonium bromide

The effect of Cibacron Blue 3GA (CB) and bovine serum albumin (BSA) as guest molecules on the microstructure of reversed micelles has been investigated with electrical conductivity measurements. CB as an affinity ligand was directly introduced to reversed micelles formed with cationic surfactant, cetyltrimethylammonium bromide (CTAB). The anionic CB has electrostatic interactions with cationic surfactant and has affinity interaction with BSA. The conductivity of reversed micellar systems increases gradually with the increase of temperature either with or without the addition of CB. No electrical percolation appears with increase of temperature or water concentration. The conductivity of reversed micellar systems decreases with the addition of CB and decreases further with the addition of both CB and BSA. The conductivity of organic phase is three orders of magnitude lower than that of aqueous phase under the same CB concentration, which indicates that CB is probably confined to the closed microdomains of reversed micellar systems. The conductivity behavior of reversed micelles has not much difference with the addition of CB and BSA either by injection method or by phase transfer. For pH<pI, reversed micelles containing no CB solubilize no BSA due to electrostatic repulsion by phase transfer method. The enhancement of BSA transfer to the reversed micelles with addition of affinity CB indicates a strong interaction between the extracted BSA and the reversed micellar phase. The improvement of selectivity should be expected with the presence of biospecific CB because the affinity interaction is the unique driving force for BSA transfer.