Rapid, Room-Temperature Formation of Crystalline Calcium Molybdate Phosphor Microparticles via Peptide-Induced Precipitation

Nature provides numerous examples of organisms that synthesize intricate mineral structures (biominerals) with micro- to nanoscale features through the use of specific biomolecules.[ 1] While such control over mineral formation under ambient conditions exceeds current man-made assembly technologies, the known biominerals (only about 60 different minerals have been identified to date) do not possess compositions that are particularly attractive for many man-made devices.[ 2] Nonetheless, nature's exquisite control over biomineral formation has inspired the search for biomolecules capable of directing the assembly of non-natural inorganic materials. Peptides that exhibit specific affinities for synthetic materials (e.g., ZnO, Cr2O3, GeO2, Ag, GaAs) have been identified by several authors through bacteriophage or cell surface display (biopanning) methods.[3] However, the use of such display methods to identify specific peptides that induce the formation of crystalline multicomponent metal oxide compounds (i.e., materials widely used in functional devices) at room temperature and ambient pressure has not been reported in the literature. In this work, a phage display method has been used to identify peptides that bind to, and promote the direct and rapid room-temperature formation of CaO MoO3 (powellite) microparticles from aqueous precursor solutions.
Pub. in Jnl. of Adv. Mater, v18 p1759-1763, 2006. Supported in part by ONR.