Biophysics

Tiny gold particles are good for transferring heat and could be a promising tool for creating localized heating in, for example, a living cell. Researchers at the Niels Bohr Institute have measured the temperature of nano-sized gold droplets with extreme precision and

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have examined their ability to melt the lipid membranes surrounding cells, paving the way for dissolving sick cells.

Gold nano-particles have a strong interaction with light in relation to their size and it is precisely their physical size that gives them different colours. Its colour is the result of how strongly a gold particle scatters and absorbs light at different wavelengths. Therefore, when the light heats up the gold particle, the colour has significance for its temperature.

It was said by one of the participants of this experiment, that, the droplets can be heated using infrared light from the optical tweezers and by turning the light up and down you can control the heat. But it is important to know the precise temperature in order to have complete control over the situation. The technique can also be used as a tool for changing temperatures in a few microseconds. Here the border surface between the two states will be very clear-cut, which is useful if you want to study cell membranes.

Source: Niels Bohr Institute

DOI: Published on 17 January 2011.

Link: http://www.nbi.ku.dk/english/news/news11/controlled_heating_of_gold_nanoparticles/