Synthesis and characterization of novel glycosurfaces by ATRP

Abstract

The direct synthesis of well defined sugar methacrylate-based homopolymer brushes with high grafting densities based on D-gluconamidoethyl methacrylate (GAMA) and 2-lactobionamidoethyl methacrylate (LAMA) from functionalized gold substrates was carried out using surface-initiated atom transfer radical polymerization (ATRP). A good control of the polymerization leading to an increase in the dry film thickness with reaction time was achieved in mixed methanol/water solvent media. However, grafted glycopolymer films of low thicknesses, which did not increase further with longer polymerization times were synthesized in water, suggesting the premature termination of the polymerization in the aqueous solvent. Attenuated total reflectance (ATR)-FTIR spectroscopy confirmed the successful grafting of the glycopolymer brushes on the modified gold substrates, while atomic force microscopy (AFM) verified that the anchored film covered the substrate surface completely and homogeneously. The surface roughness found by AFM was below 1 nm suggesting the preparation of very smooth glycopolymer films. The grafting of the glycopolymer chains onto the gold substrates afforded an increase in the surface hydrophilicity as confirmed by contact angle measurements. The synthesized glycopolymer films exhibited strong binding interactions with specific lectins via the “glycocluster” effect.