Sialic Acid Detection with Fluorescent Boronic Acids

The sialic acid family of cell surface carbohydrates are important to maintaining healthy cellular communication and play a role in cancer and infectious diseases. Monitoring of cell sialylation and free sialic acids can serve as important biomarkers for several diseases. The glycerol tail of the common sialic acid N-acetylneuraminic acid has an affinity for boronic acids and this interaction has been used to detect this sugar fluorescently. This review covers the development of small molecule fluorophores to signal sialic acid binding by boronates and the application of such molecules to detection of cell surface sialylation. In addition, boronic acids have frequently been incorporated into gold nanoparticles to detect both free and cell-surface sialic acids through multivalent interactions.