Interactions between Oat β-Glucan and Calcofluor Characterized by Spectroscopic Method

This paper describes the binding of Calcofluor, a fluorescent probe, to oat β-glucan in buffer solutions. The binding equilibrium constant (K), the total number of binding sites per β-glucan molecule (N), and the average binding number of Calcofluor per β-glucan molecule (n) were determined by UV spectroscopic method. The results indicate that the association of Calcofluor and β-glucan is driven by both enthalpy and entropy and that the process involves hydrogen bonding, van der Waals forces, and hydrophobic interaction. Higher buffer concentration and NaCl facilitate the binding of Calcofluor to β-glucan. The adsorption isotherm fits a Langmuir model quite well.