University of California-Davis scientists say the nanoparticle is luminescent, magnetic and inexpensive to make, and can be tagged with antibodies.
The new nanoparticles consist of a magnetic core of iron oxide or iron/neodymium/cobalt oxide coated in a shell of europium and gadolinium oxide. When stimulated with a laser, europium emits red light at a very specific wavelength.
The researchers say the nanoparticles can be manipulated with magnets and detected by fluorescence and might also be used as part of an assay with other fluorescent labels.
The built-in europium luminescence acts as an internal standard, making it easier to carry out accurate quantitative assays, said Ian Kennedy, professor of mechanical and aeronautical engineering and senior author of a paper describing the work.
The particles can also be coated with short pieces of DNA and used for genetic analysis. Researchers are exploring other uses, including testing for bioterrorism agents.
The research is to appear in the Feb. 7 issue of the journal Nanotechnology.