title: Photocatalytic synthesis of copper colloids from CuII by the ferrihydrite core of ferritin.
abstract: The iron-storage protein ferritin encapsulates a nanoparticle of iron oxide. The size and properties of these nanoparticles can be adjusted by controlled oxidative hydrolysis reactions of Fe(II). This mineralized ferritin protein cage has previously been shown to act as an effective photocatalyst for reduction of Cr(VI). In the present work, we demonstrate that Fe(O)OH-mineralized ferritin catalyzes the photoreduction of Cu(II) to form a stable, air-sensitive, colloidal dispersion of Cu(0). In addition, the particle sizes of the Cu colloids can be controlled by varying the ratio of Cu(II) to ferritin. This illustrates an important principle, namely that the properties of one preformed material can be utilized for the specific synthesis of a second material, thus tailoring the desired physical properties of the final products. This procedure represents a multistep materials synthesis: the formation of a new nanomaterial from a catalytic precursor.
authors.affiliation: Department of Chemistry and Biochemistry, Department of Plant Sciences, and Center for Bio-Inspired Nanomaterials, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ensign
authors.forename: Mark
authors.initials: M
authors.lastname: Young
authors.forename: Trevor
authors.initials: T
authors.lastname: Douglas
mesh_terms: D002384:Catalysis; D003102:Colloids / Q000138:chemical synthesis*; D003300:Copper / Q000737:chemistry*; D019327:Copper Sulfate; D005290:Ferric Compounds / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry*; D008854:Microscopy, Electron; D036103:Nanotechnology; D010084:Oxidation-Reduction; D010316:Particle Size; D010782:Photolysis; D013053:Spectrophotometry; D013997:Time Factors
chemical_list: D003102:Colloids; D005290:Ferric Compounds; C000499:ferric oxide; D003300:Copper; C092844:ferric oxyhydroxide; D005293:Ferritins; D019327:Copper Sulfate; C000520:cuprous oxide