Aqueous Near-Infrared Fluorescent Composites Based on Apoferritin-Encapsulated PbS Quantum Dots

PbS nanocrystals entrapped in the hollow core of apoferritin protein cages are synthesized in aqueous solution by both reassembly and nanoreactor routes. In both cases, apoferritin limits the size of the PbS quantum dot it can encapsulate to 8 nm and provides a route to the creation of a stable near-infrared fluorescent composite.