Alloys of iron and cobalt generate powerful magnetic signals that could be useful in nanoparticles designed to detect tumors using magnetic resonance imaging (MRI). However, naked iron-cobalt nanoparticles turn out to be chemically active materials, making them unsuitable for use in the body, and efforts to add any number of protective coatings have failed to produce biocompatible nanoparticles.

To solve this problem, researchers at the Center for Cancer Nanotechnology Excellence Focused on Therapy Response, based at Stanford University [profile], used a high-temperature vapor deposition process to construct a carbon-coated iron/cobalt nanoparticle that can safely image tumors in living animals. Moreover, these nanoparticles can absorb near-infrared light and generate heat, raising the possibility that they could not only image tumors, but kill them by cooking them to death. The results of this effort appear in the journal Nature Materials.