Synthesis and Characterization of Glyco-SAMs on Gold Nanoparticles: A Modular Approach Towards Glycan-Based Recognition Studies

Within recent years, the interest in tools to investigate carbohydrate-protein (CPI) and carbohydrate-carbohydrate interactions (CCI) has increased significantly. For the investigation of CPI and CCI, several techniques employing different linking methods are available. For mimicking the glycocalyx self-assembled monolayer (SAM) formation of carbohydrate derivatives on gold nanoparticles is most appropriate. In contrast to methods for glyco-SAM formation used previously to analyze CPI/CCI, the novel approach allows for a facile and rapid synthesis to link spacers and carbohydrate derivatives and enhances the binding event by controlling the amount and orientation of ligand. For immobilization on biorepulsive aminooxy functionalized gold nanoparticles by oxime coupling, diverse aldehyde-functionalized glycan structures of mono-, di-, and complex trisaccharides were synthesized, employing several facile steps including olefin metathesis. Effective immobilization and first binding studies are presented for the lectin concanavalin A. This novel and advantageous immobilization method is presently employed in various biomimetic studies of carbohydrates and carbohydrate-based array development for diagnostics and screening.