The structure of gold nanoparticles has been largely unknown for over a decade. A current study helps to understand the stability, composition as well as electronic, chemical and optical properties of the particles.
The research group, led by Professor Hannu Häkkinen of the Nanoscience Centre of the University of Jyväskylä, says the results of the study can be utilized in medicine, biomolecule research and nanoelectronics. With the help of gold nanoparticles it is, for instance, possible to destroy cancer cells.
The particles are able to attach themselves to cancer cells due to a biologically compatible molecular overlayer. With the help of laser it is possible to heat the particles so much that the attached cancer cells die. Particles can also be used as a tracer when looking at biomolecules with an electron microscope. Nanoelectronics, for its part, can use gold nanoparticles as components in electrical circuits.
"My personal dream came true late last year when a group led by Roger Kornberg at Stanford University made a breakthrough experiment determining the atomic structure of gold nanoparticles of a certain size. The structure resembled the prediction our research group had already earlier published. In the recent study we were able to comprehend why nature generates exactly these kinds of particles. The size of one particle is 1-3 nanometers, and since they behave in many respects like giant atoms, we call them superatoms in our study", Häkkinen explains. "Our study would not have been possible without the extensive high performance computing resources of the national IT centres of Finland, Germany and Sweden. The study took up quite a lot of computation time, but it was well worth the effort. I believe that our theoretical model on the stability of the gold nanoparticles will prove itself very useful in many interdisciplinary fields of research."
In addition to Häkkinen’s research group researchers from Stanford University, Chalmers University of Technology in Göteborg and Georgia Institute of Technology in Atlanta collaborated in the study. In Finland the research has been funded by the Academy of Finland, the Finnish IT center for science and DEISA, Distributed European Infrastructure for Supercomputing Applications.
Article: "A unified view of ligand-protected gold clusters as superatom complexes", PNAS July 8, 2008 vol. 105 no. 27 9157-9162.
