Protein-Templated Near-Infrared Emitting Fe Nanoclusters Exhibit Superparamagnetism at Room Temperature

Water soluble Fe nanoclusters in the size ranging from 1.4 to 5 nm, exhibiting photoemission in the visible (λem=450 nm) and near-infrared region (λem=845 nm) have been synthesized with the use of mixed proteins. The protein-templated Fe nanoclusters exhibit superparamagnetism at room temperature, offering potential applications in bio-labeling and imaging.