Selective immobilization of biomolecules onto an activated polymeric adlayer.
The authors report a facile method for the selective immobilization of biomolecules onto a gold surface that was preactivated by a polymeric adlayer. The polymeric adlayer was designed to perform triple functions: high resistance to nonspecific protein adsorption, efficient surface anchoring, and subsequent covalent attachment of biomolecules. For this purpose, a random copolymer, poly(PEGMA-r-NAS), was synthesized by radical polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and N-acryloxysuccinimide (NAS). In the first step, the polymeric adlayer was formed onto amine-terminated self-assembled monolayers (SAMs) on gold through covalent bond formation between reactive N-hydroxysuccinimide (NHS) ester of the copolymer and the amine of the SAMs. In the second step, amine-bearing biotin as a model biomolecule was covalently attached onto the polymeric adlayer that still contained unreacted NHS esters. The degrees of the binding sensitivity for a target protein and the nonspecific binding for four model proteins on the biotinylated polymeric adlayer were examined by surface plasmon resonance spectroscopy. Finally, the specific immobilization of rhodamin (TRITC)-conjugated streptavidin on the biotinylated polymeric adlayer was achieved by a simple microcontact printing technique, resulting in well-defined patterns of the protein.
Lee
Bong Soo
BS
Department of Chemistry and School of Molecular Science (BK21), Center for Molecular Design and Synthesis, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
Park
Sangjin
S
Lee
Kyung-Bok
KB
Jon
Sangyong
S
Choi
Insung S
IS