Appropriating cellulose fibres from cotton and crystallizing them, scientists at Pacific Northwest National Laboratory have grown never-before-seen configurations of metal crystals that show promise as components in biosensors, biological imaging, drug delivery and catalytic converters. Deriving the desired chemical and physical properties necessary for those applications hinges on the uniform size of the metal crystals. Depending on the metal, they must be between 2 and 200 nanometers, Yongsoon Shin, a staff scientist at the Department of Energy laboratory in Richland, Wash., reported Monday at the national meeting of the American Chemical Society. PNNL laboratory fellow Gregory Exarhos led the research.