A new class of water-soluble quantum dots made from small numbers of gold atoms could be the basis for a new biological labeling system with narrower excitation spectra, smaller particle size and fluorescence comparable to systems based on semiconductor quantum dots.
Providing the “missing link” between atomic and nanoparticle behavior in noble metals, these multi-electron “artificial atoms” could also serve as light-emitting sources in nanoscale optoelectronics and in energy transfer pairs. “We have discovered a new class of quantum dots that are water soluble, strongly fluorescent, and display discrete excitation and emission spectra that make them potentially very useful for biological labeling,” said Robert Dickson, associate professor in the School of Chemistry and Biochemistry at the Georgia Institute of Technology. “Their potential applications are really complementary to those of semiconductor quantum dots.”
The gold nanodots are made up of 5, 8, 13, 23 or 31 atoms, each size fluorescing at a different wavelength to produce ultraviolet, blue, green, red and infrared emissions, respectively. The fluorescence energy varies according to the radius of the quantum dot, with the smallest structures the most efficient at light emission.
Mars 2020 mission to use smart methods to seek signs of past life
17.08.2017 | Goldschmidt Conference
Gold shines through properties of nano biosensors
17.08.2017 | American Institute of Physics
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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17.08.2017 | Physics and Astronomy
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17.08.2017 | Physics and Astronomy