- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
|Similar to the way water backjets eject droplets of water on the surface of a pond, powerful laser pulses can locally melt gold nanostructures and produce gold nanojets, ejecting perfectly spherical gold nanodroplets.|
KU Leuven researcher Ventsislav Valev and an international team of scientists have developed a new method for optical manipulation of matter at the nanoscale. Using ‘plasmonic hotspots' - regions with electric current that heat up very locally - gold nanostructures can be melted and made to produce the smallest nanojets ever observed. The tiny gold nanodroplets formed in the nanojets, are perfectly spherical, which makes them interesting for applications in medicine.
The ‘backjet' phenomenon on which the method turns can be compared to a pebble being dropped into water. Tightly focused ultrafast laser pulses carry sufficient energy to locally melt the surface of a gold film. When a laser pulse of light hits the film, a nanoscale backjet - a nanojet - of molten gold surges upward.
As the name suggests, nanojets on the surface of a homogeneous gold film are incredibly small, their size being determined by the distribution of energy in the light pulse. This distribution of energy is in turn dependent on the wavelength of light. Initially, scientists anticipated that nanojets could not be significantly smaller than the wavelength of light. In this study however, Ventsislav Valev and his colleagues show that nanojets can in fact be made much smaller with the help of ‘plasmonic hotspots'.
Plasmonic hotspots are regions on the surface of metal nanostructures where light causes very strong oscillation of the electrons. Because electron oscillations constitute an electric current and because electric currents heat up the material the same way an electric stove heats up in the kitchen, the plasmonic hotspots are extremely hot. So hot that they can melt the gold in a spot much smaller than the wavelength of light. Dr. Valev and his colleagues were successfully able to demonstrate that this tiny little pool of molten gold can give rise to the smallest nanojets ever observed.
The gold nanodroplets propelled upward by the nanojets solidify in flight, producing perfectly spherical nanoparticles. These gold nanodroplets can be collected and used for medical applications including cancer treatment. The nanoparticles can be attached to molecules and injected in the blood. Once the molecules attach to cancer cells, light can be used to heat up the gold nanodroplets and destroy the cancer cells. Currently, the gold nanoparticles used in medications are chemically synthesised. These chemically synthesised gold nanoparticles have an unavoidably granular aspect. Conversely, gold nanodroplets created by the plasmonic nanojet method detailed by Dr. Valev and his colleagues are perfectly spherical, ensuring a better efficiency.
The study was conducted in collaboration with scientists from Germany, the United Kingdom, Bulgaria, Russia and Singapore and is published in the latest edition of the journal Advanced Materials.
For more information, please click here
Dr. Ventsislav Valev
Molecular Imaging and Photonics
Faculty of Science
University of Leuven
Griet Van der Perre
+32 16 32 40 08
Copyright © AlphaGalileoIf you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Full bibliographic informationVentsislav K. Valev, Denitza Denkova, Xuezhi Zheng, Arseniy I. Kuznetsov, Carsten Reinhardt, Boris N. Chichkov, Gichka Tsutsumanova, Edward J. Osley, Veselin Petkov, Ben De Clercq, Alejandro V. Silhanek, Yogesh Jeyaram, Vladimir Volskiy, Paul A. Warburton, Guy A. E. Vandenbosch, Stoyan Russev, Oleg A. Aktsipetrov, Marcel Ameloot, Victor V. Moshchalkov, Thierry Verbiest, Plasmon-Enhanced Sub-Wavelength Laser Ablation: Plasmonic Nanojets, Advanced Materials, Article first published online: 9 JAN 2012, DOI: 10.1002/adma.201103807:
|Related News Press|
News and information
Nuclear pores captured on film: Using an ultra fast-scanning atomic force microscope, researchers from the University of Basel have filmed 'living' nuclear pore complexes at work for the first time May 3rd, 2016
A compact, efficient single photon source that operates at ambient temperatures on a chip: Highly directional single photon source concept is expected to lead to a significant progress in producing compact, cheap, and efficient sources of quantum information bits for future appls May 3rd, 2016
Exploring phosphorene, a promising new material April 29th, 2016
Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016
Cooling graphene-based film close to pilot-scale production April 30th, 2016