Crystallographic Control in Biomineralized Inorganic Nanostructures

Scientific Accomplishment

Structural features of biological molecules can be imprinted on inorganic crystals using a biomineralization procedure based on synthetic biomolecular templates. The remarkable feature of the work is evidenced in the hierarchical organization of 1-D DNA in a 2-D lipid bilayer in a way that provides control over the size and shape of CdS crystals and the direction in which they grow. The technique, which was developed at the University of Illinois, Urbana-Champaign (UIUC), may lead to custom-designed crystals with useful electronic, magnetic, and optical properties. At the heart of the new crystal growth method are electrostatic forces that drive the material's synthesis steps. To prepare the templates, the UIUC researchers combine anionic DNA and cationic membranes that are composed of a mixture of lipids. The components self-assemble in solution, forming lamellar structures (stacks of sheets) in which DNA strands are confined between the lipid layers.

This work demonstrated for the first time that it's possible to gain crystallographic control of a biomineralized phase by directly imprinting molecular details from a biological molecule onto an inorganic crystal. Most notable, the method enables the shape of a nanoparticle to be controlled independently from its crystallographic orientation.

Significance

The precise control of nanoscale structure is central competency of biology. These organizational motifs support in critical ways the processes needed to sustain life. The methods used to organize the structures of materials used in technology are, for the most part, far less capable of embedding complexity and selecting precise arrangements at the nanoscale level. The current research demonstrates a method that exploits the highly developed materials of the natural world to provide the templates on which to organize the structures of high-technology materials.

Performers

Senior FS-MRL PI: Gerard Wong