Comparing Self-Assembling and Covalent Fluorescent Boronolectins for the Detection of Free Sialic Acid

A self-assembling fluorescence sensor with boronic acid functionalities was tested for binding selectivity to the monosaccharide, sialic acid. Working from a previously reported system, a self-assembling system could form an imine in situ that enables a conjugated fluorophore to display a measurable change in fluorescence in the presence of monosaccharide. However, further examination showed that free sugars give a similar fluorescence response to just the m-aminophenylboronic acid moiety on its own. Still, such a self-assembly method may be applicable to cell surface saccharide sensing as aldehydes and ketones are noticeably absent on most cells' exteriors. The original covalent receptor appears best suited for the detection of free sialic acid.