Synthesis of Glycopolymer Gold Nanoparticles Decorated with Oligosaccharides via a Protecting-group-free Process and Their Specific Recognition by Lectins

Glycopolymers with various pendant oligosaccharides were synthesized from free saccharides without protection of the saccharide hydroxy and carboxy groups. The strategy involved direct anomeric azidation of the free saccharides, copper-catalyzed azide-alkyne cycloaddition, and reversible addition-fragmentation chain transfer polymerization using the glycomonomers and trithiocarbonate derivative as a chain transfer agent. After reducing the trithiocarbonate terminal group on the polymer backbone, the resulting thiol-terminated glycopolymers were immobilized on gold nanoparticles via Au-S bound formation. The glycopolymer-decorated gold nanoparticles in aqueous suspension were specifically recognized by the corresponding lectin, with no measurable nonspecific binding.