Probing disaccharide selectivity with modular fluorescent sensors

Six modular photoinduced electron transfer (PET) sensors bearing two phenylboronic acid receptors have been evaluated as fluorescent disaccharide sensors. The length of linker separating the two boronic acid moieties was varied and the sensors’ interaction with disaccharides assessed via fluorescence spectroscopy. It was shown that saccharide selectivity was influenced by the choice of linker length. Diboronic acid sensors 3n also displayed significant specificity for the disaccharides linked to the carbon on the 3rd or 6th position (as numbered from the anomeric centre) over those linked at the 4th position.