Gold-conjugated protein nanoarrays through block-copolymer lithography: from fabrication to biosensor design

Abstract

A method to immobilize proteins at predefined position using gold-conjugated protein nanoarrays was investigated. Two different proteins, gold nanoparticle-conjugated streptavidin and gold-conjugated protein G molecules were selected as model proteins in the study. The individual protein molecules are immobilized and stabilized with inherent spacing without interfering with the intermolecular interactions. The electrochemical behavior of the exposed gold film was studied as a function of the RIE time to verify whether the ordered pore region is exposed to the underlying surface, which is critical for the immobilization of probe biomolecules. The selective deposition of SA-AuNPs on the biotin-modified surface was further supported by CV analysis, where the voltammetric peak current associated with the redox pair became substantially lower as the surface became blocked by adsorbed streptavidin molecule. This method provides a promising tool for biosensor applications.