Interaction between acridine orange and sulphated polysaccharides

Abstract

This paper described the interaction between Acridine Orange and the sodium polysaccharides sulphates; the sodium salts of α- and β-cyclodextrin sulphate, amylose or amylopectin sulphate. α- and β-cyclodextrin sulphate have a rigid polymer structure. But amylose sulphate and amylopectin sulphate have flexible polymer structures in the aqueous solutions. The binding data show that the positive entropy difference of 5 e.u. between cyclodextrin sulphate and amylose sulphate correspond to the conformation changes of the polymers on dye binding. And the positive entropy change of α- and β-cyclodextrin must be caused by the hydrophobic bonding with the destruction of the water structure about polymers.

Also, the saturated binding sites are corresponding to the degree of the sulphated sites. These results show that the dye binding is principally caused by the electrostatic interaction.