Synthesis of inorganic nanowires by using peptide nanotubes as the templates via biologic recognition
Nanomaterials and nanoscale engineering will play a critical role in the future of materials science, electronic technology and biotechnology. Inspired by nature, biomineralization is becoming an important technique to synthesize inorganic nanomaterials. This is a recognization process which is based on molecular complementarity between protein and specific crystal phases of metals or semiconductors. This approach can produce nanomaterials with precisely controlled morphology and crystalline structure under mild conditions. In this dissertation, sequenced histidine-rich peptides are used to fabricate morphology-controlled nanocrystals on the surface. Various inorganic nanocrystals are produced accurately, efficiently and reproducibly by choosing different peptide sequences for different metals. Biomineralization of nanotubes is achieved by incorporating these sequenced histidine-rich peptides onto templated peptide nanotubes. The biological recognition of the specific peptide sequences toward particular metals and semiconductor leads to the efficient coatings of such inorganic nanocrystals as Ag, Pt, Cu, Ni and ZnS on the nanotubes. This method allows for the synthesis of nanotubes uniformly coated by highly crystalline metal nanocrystals with a high-density surface coverage. It has been demonstrated that the size, shape and packing density of the nanocrystals can be regulated via changes in the pH of the solution, which leads to conformational changes in the peptide. By this means, different inorganic nanowires can be synthesized with tunable surface morphology which results in tunable physical properties that could be used as the building blocks for the fabrication of nanodevices.