pH-responsive Adsorption and Dissociation of Sialic Acid Expressed Protein on Boronic Acid Immobilized Surface.

Detection and isolation of sialic acid (SA) over-expressed biomolecules is of continuous interest in cancer-related research. Boronic acid-based SA-recognition chemistry provides a synthetic molecular basis for such techniques. 5-Boronopicolinic acid, a derivative with the reportedly highest SA-binding strength, was immobilized to a gold surface and studied for its interaction with fetuin, a blood-circulating glycoprotein implicated in cancers. A submicron-molar level sensitivity was achievable, while the sample could be readily dissociated by modulating the pH. [ABSTRACT FROM AUTHOR]