Materials Specificity and Directed Assembly of a Gold‐Binding Peptide

Abstract

AbstractAdsorption studies of a genetically engineered gold‐binding peptide, GBP1, were carried out using a quartz‐crystal microbalance (QCM) to quantify its molecular affinity to noble metals. The peptide showed higher adsorption onto and lower desorption from a gold surface compared to a platinum substrate. The material specificity, that is, the preferential adsorption, of GBP1 was also demonstrated using gold and platinum micropatterned on a silicon wafer containing native oxide. The biotinylated three‐repeat units of GBP1 were preferentially adsorbed onto gold regions delineated using streptavidin‐conjugated quantum dots (SAQDs). These experiments not only demonstrate that an inorganic‐binding peptide could preferentially adsorb onto a metal (Au) rather than an oxide (SiO2) but also onto one noble metal (Au) over another (Pt). This result shows the utility of an engineered peptide as a molecular erector in the directed immobilization of a nanoscale hybrid entity (SAQDs) over selected regions (Au) on a fairly complex substrate (Au and Pt micropatterned regions on silica). The selective and controlled adsorption of inorganic‐binding peptides may have significant implications in nano‐ and nanobiotechnology, where they could be genetically tailored for specific use in the development of self‐assembled molecular systems.