Researchers at Kansas University have developed a new method for optical manipulation of matter at the nanoscale, creating perfectly spherical gold nanodroplets.
The nanodroplets, which could improve medical applications for cancer treatments, are the smallest-ever nanojets. They could be used in cancer treatment by attaching the nanoparticles to molecules and injecting them into the blood. The molecules then attach to the cancer cells, with the light heating up the gold nanodroplets destroying cancer cells.
The perfectly spherical shape makes them of particular interest for applications in medicine, as the current, chemically synthesised gold nanoparticles, have an unavoidably granualar aspect. Gold nanodropelts created by the plasmonic nanojet method detailed by Dr Neven Valev and his colleagues are perfectly spherical, which ensures better efficiency.
Plasmonic hotspots were able to give rise to the smallest nanojets ever observed because of their extreme heat.
This is caused by electron oscillations, which constitute an electric current, and are therefore heat up in the same way that an electric stove heats up in the kitchen. The extreme heat can melt the gold in a spot much smaller than the wavelength of light, something that has not been achievable before.
Posted by Fiona Griffiths