These gold nanoclusters are chemically protected by
An international research team from Switzerland, Italy, the United States and Germany has now shown that the fluorescence is an intrinsic property of the gold nanoparticles themselves. The researchers used Au20, gold nanoparticles with a tetrahedral structure. Their findings were reported this week in the Journal of Chemical Physics, from AIP Publishing.
"We present the first optical absorption, excitation and fluorescence spectra of bare Au20," said Harald Brune, head of the Institute of Physics at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and corresponding author of the paper. "Our results strongly suggest that the metal core in the ligand-protected clusters used for biosensing and biolabeling is at the origin of their fluorescence."
The researchers created a beam of bare Au20 clusters by combining a cluster aggregation source with a custom-designed ion optic and mass selection process. It is difficult to probe the optical properties of these clusters in the gas phase, given the poor signal-to-noise ratio. To address this issue, the researchers embedded them into a solid neon matrix. This was achieved by depositing the cluster beam with a neon background gas that condensed onto a cold surface held at 6 kelvins (about -267 degrees Celsius) while the clusters were landing there.
Read more at: https://phys.org/news/2017-08-gold-properties-nano-biosensors.html#jCp
Social Plugin