Biologically Inspired Materials for Electro-Responsive Coatings and the Photo-Oxidation of Water

摘要

Evolving out of research on biomineralization, a new field devoted to studying the interactions between inorganic materials and proteins is emerging. In natural systems proteins are responsible for the assembly of complex hierarchical structures such as the nacre of abalone. Tools such as phage and yeast display libraries have enabled the combinatorial screening of peptides against a multitude of materials to which natural systems typically have no exposure. These techniques have yielded peptides that can bind and assemble technologically relevant materials such as gold and CdS. In this work, combinatorial phage and yeast display libraries are used to identify peptide sequences that bind to electrode materials and metal oxides. As in nature it is observed that the context of a particular peptide dramatically influences its properties. While a peptide sequence may exhibit good adhesion to a particular surface when displayed on yeast, the same peptide may have little affinity towards that same surface when displayed on bacteriophage. To probe the interactions between peptides and materials in a context-free environment, rationally designed synthetic peptides were screened against a number of inorganic materials. A synthetic peptide covalently linked to either microspheres, quantum dots, or a polymer, was able to mediate adhesion of those entities to electrode surfaces. In nature, proteins play important roles beyond biomineralization. For example membrane proteins contain voltage-gated ion channels that open and close in response to a voltage bias. Inspired by the electro-responsive activity of ion channels, the interactions between peptides, surfaces and electric fields was investigated. The peptide sequences that exhibited significant adhesion to metal oxides were dominated by positively charged residues.