A grand challenge in nanomaterials manufacturing is the reliable, scalable and reproducible production of metallic nanostructures. The ability to program the synthesis and position of such nanostructures will enable the development of innovative materials for energy storage, light-harvesting or catalysis. Despite a high degree of interest in controlling the growth and placement of nanoparticles using biological materials as templates, it is currently difficult to control the size, shape and position of the resulting inorganic components. With this award, the research team will use engineered protein crystals, highly ordered assemblies of trillions of monomers, as "molds" to direct and limit the growth patterns of guest nanoparticles. Both the resulting nanostructures and the hybrid crystalline assembly of nanoparticles thereof, have potential useful applications. For example, inorganic structures formed within the solvent channels of protein crystals could result in ultra-high surface area materials for catalysis or battery applications. This research will provide interdisciplinary educational training opportunities for undergraduate and graduate students in cutting-edge areas of bionanotechnology, molecular modeling, nanostructure synthesis, as well as nanostructure imaging and analysis. Results from this research will therefore benefit both the U.S. economy and society.
Nanoparticle growth is a nucleation phenomenon, making it technically challenging to grow them with uniform size or low symmetry. The research team will decouple nucleation from growth, using well-established affinity interactions to "plant" seed nanoparticles at specific sites within the protein lattice. Seeded nuclei will then be subjected to controlled growth within the anisotropic protein matrix. The resulting hybrid crystals will be characterized using multiple techniques including x-ray diffraction, elemental analysis, and electron microscopy. Nanoparticles released from the host crystals will likewise be characterized via electron microscopy. In comparison with existing approaches for the template-directed deposition of inorganic structures, crystalline scaffolds will provide a higher degree of order and the unique possibility of high-resolution structure determination.
