TU Delft makes magnetic nanoparticles from precious metals

Researchers at Technische Universiteit Delft (also known as TU Delft  and Delft University of Technology) have succeeded in developing a simple method to make nanoparticles of precious metals magnetic.

This type of nanoparticle, or clusters of nanoparticles, could prove extremely useful for a range of applications, including improved MRI research. The researchers published an article about their discovery in this week's online edition of the scientific journal Langmuir.

The method was actually discovered by coincidence during the standard production of nanoparticles of precious metals at TU Delft, which are needed for fuel cell research, among other things.

If the conventional method of making these nanoparticles is carried out in a strong magnetic field, it turns out that the nanoparticles, or clusters of nanoparticles, actually become magnetic themselves.

The Delft researchers, led by Dr Ger Koper, have now demonstrated the technique for gold, silver and copper nanoparticles. The scientists were also successful in excluding the possibility that the magnetism identified was actually caused by impurities in the particles. The strength of the magnetism is comparable with that of iron.

This is of particular interest, especially in certain medical applications. For example, tiny magnetic particles are used in contrast agents for MRI scans, but these have the disadvantage of being toxic to the human body. Precious metals do not have this disadvantage since they do not react (or only slightly) with other substances.