Enhanced Binding and Biosensing of Carbohydrate-Functionalized Monolayers to Target Proteins by Surface Molecular Imprinting

Abstract

Concanavalin A (Con A) binding to the surfaces of mannose-functionalized binary monolayers was enhanced by surface molecular imprinting technique. The protein surface imprinting was prepared from binary Langmuir monolayers at the air-water interface through lateral reorganization of glycolipids directed by Con A in the subphase solution to form more specific bivalent binding sites, followed by horizontal immobilization of the binary monolayers and preservation of the enhanced affinity. The favorable spatial arrangement of the mannose ligands through lateral delivery matched well with protein binding pockets, and the steric crowding/hindrance of neighboring ligands was minimized. The amounts of specifically bound proteins on the imprint surfaces are almost independent of surface density of the ligands, in contrast to the dependence of the bound amounts on surface density of the ligands for the control surfaces. The benefits of the protein surface imprinting included excellent mass transfer, ease of integration into sensor systems, directed creation of imprint sites, and biologically friendly aqueous media. This strategy generated tailor-made surfaces with high protein affinity and opens the possibility of surface design of intellectual materials and preparation of biosensors.