Carbohydrate-based amphiphilic diblock copolymers with pyridine for the sensitive detection of protein binding

Glycopolymers are useful macromolecules for presenting carbohydrates in multivalent form. Here, amphiphilic block copolymers consisting of hydrophilic lactose and hydrophobic pyridine were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). RAFT polymerization of 2-O-methacryloyloxyethyl-(β-D-lactoseheptaacetate) (2-O-MALac) was performed using cumyl dithiobenzoate (CDB) as the chain transfer agent to give well-defined glycopolymers. The livingness of the process was further demonstrated by successfully chain-extending one of obtained glycopolymers with 4-pyridyl methyl methacrylate affording narrow dispersed diblocks. With the obtained block copolymers, a glycosurface was generated on the gold surface of quartz crystal microbalance (QCM) through self-assembled strategy by the use of gold affinitive pyridine functional group. Furthermore, the resulting glycosurface was used to detect the binding of lactose specific lectin, ricinus communis agglutinin (RCA120) without non-specific protein adsorption.