Fluorophore-glucan conjugate for oligosaccharide sensing in aqueous media

Abstract

The ability to sense saccharides in aqueous media using conventional supramolecular approaches was a turning point in modern chemistry. Herein, we performed oligosaccharide sensing using fluorophore-modified branched glucans. Through the newly developed glucan-based chemosensor, acarbose sensing was achieved in a selectively and sensitive manner. The optical properties and morphological changes in the chemosensor were investigated, revealing that the globule-to-coaggregation process plays a key role in oligosaccharide sensing. The fluorophore-modified glucan, TPE-6BG3 adopts an extended, random-coiled form in DMSO, which does not fluoresce. The morphology of the TPE-6BG3 chemosensor changes drastically to a dynamic globule in aqueous media. The dynamic, “induced-fit” globule selectively and sensitively recognizes the medicinally-useful tetrasaccharide, acarbose via glucan-saccharide coaggregation.