A colourful way to size up nanoparticles

Nanoparticles can be sized thanks to the localised surface plasmon resonance (LSPR) effect observed in gold, silver and copper particles. This phenomenon arises as incident light interacts with surface electrons and is scattered. It forms the basis of many of the applications of nanoparticles in photonics, for instance.

The team explains that the approach is more convenient and less time-consuming than other techniques. They add that it is possible to use the technique in real-world environments rather than requiring pristine laboratory conditions and a scanning electron microscope. And they have now validated their size estimates against precise measurements and claim that an error margin of less than 5 nm is possible.

‘I do believe this work represents a very elegant new method for estimating gold nanoparticle size according to their light scattering optical properties,’ Qun Huo of the University of Central Florida tells Chemistry World. Huo specialises in the synthesis and properties of nanoparticles. ‘The principle behind the method has been known within the community for a while,’ she adds. ‘However, the authors of this paper have managed to introduce mathematical software to analyse the optical properties and so correlate the information with nanoparticle size. This new tool could be very valuable in further advancing gold nanoparticle-enabled bioimaging and chemical sensing applications.’

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