Photo-click immobilization on quartz crystal microbalance sensors for selective carbohydrate-protein interaction analyses.

A photoclick method based on azide photoligation and Cu-catalyzed azide-alkyne cycloaddition has been evaluated for the immobilization of carbohydrates to polymeric materials. The biomolecular recognition properties of the materials have been investigated with regard to applicable polymeric substrates and selectivity of protein binding. The method was used to functionalize a range of polymeric surfaces (polystyrene, polyacrylamide, poly(ethylene glycol), poly(2-ethyl-2-oxazoline), and polypropene) with various carbohydrate structures (based on α-D-mannose, β-D-galactose, and N-acetyl-β-D-glucosamine). The functionalized surfaces were evaluated in real-time studies of protein-carbohydrate interactions using a quartz crystal microbalance flow-through system with a series of different carbohydrate-binding proteins (lectins). The method proved to be robust and versatile, resulting in a range of efficient sensors showing high and predictable protein selectivities.