Analysis of binding properties between β-cyclodextrin bipyridine-ruthenium derivative and vitamins by their fluorescence spectra

This paper presents a research of the binding interaction of a new synthetized β-cyclodextrin bipyridine-ruthenium derivative[β-CD-Ru(bpy)₃] with a series of vitamins using fluorescent spectrometry. The performance of fluorescence emission of β-CD-Ru(bpy)₃ was excellent due to the existence of the center of bipyridine-ruthenium. Based on the effect of molecular recognition between β-cyclodextrin and guest molecule, the fluorescence quenching occured because of the energy transfer between the β-CD-Ru(bpy)₃ and the vitamin when a kind of vitamin was added. According to the quantitative value of fluorescence quenching, the binding constants of the new derivative with respect to various vitamins were determined by Benesi-Hildebrand Equation. The results show that the binding capacities of the vitamins with β-CD-Ru(bpy)₃ were in a descending sequence of VB₁₂>VK₃>VC>VA.