Biological specific recognition of glycopolymer- modified interfaces by RAFT living radical polymerization

Glycopolymers with α-galactose (α-Gal) and α-mannose (α-Man) were synthesized by means of living radical polymerization with a reversible addition-fragment chain transfer reagent, and the thin-layer formation of glycopolymers was investigated in terms of protein recognition abilities. Thiol-terminated glycopolymers formed a thin layer of about 2.5 nm in thickness on a gold substrate, and the glycopolymer thin layer showed specific interaction with sugar recognition proteins (lectins and Shiga toxins (Stxs)). The interactions were highly specific, and the signal-to-noise ratio of protein recognition was greater than 16. Glycopolymer-substituted gold nanoparticles (GNPs) also showed biorecognition abilities and protein-specific aggregation. The protein recognition abilities of the GNPs were also analyzed. The glycopolymer-substituted GNPs were utilized for signal amplification of surface plasmon resonance (SPR) to detect protein-saccharide recognition. The glycopolymer with α-Gal showed a strong interaction with Stxs according to SPR measurements, suggesting a possible application of α-Gal-substituted GNPs in Stx-1 biosensing. Glycopolymer-substituted gold substrates were prepared by means of living radical polymerization with a reversible addition-fragment chain transfer (RAFT) reagent. Thiol-terminated glycopolymers were bound to the gold substrate to yield the polymer-substituted interface. In the case of the gold substrate, the interactions with proteins (lectins and Shiga toxins) were analyzed by surface plasmon resonance (SPR). The interactions were highly specific and the signal-to-noise ratio of protein recognition was more than 16.