Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Controlled heating of gold nanoparticles

The heating of gold nanoparticles by absorption of infrared light in an optical trap has now been accurately determined by researchers at the Niels Bohr Institute. The heat is difficult to ascertain as it decreases
by approximately half each step of distance the particle-size away from the surface.
The heating of gold nanoparticles by absorption of infrared light in an optical trap has now been accurately determined by researchers at the Niels Bohr Institute. The heat is difficult to ascertain as it decreases by approximately half each step of distance the particle-size away from the surface.

Abstract:
Tiny gold particles are good for transferring heat and could be a promising tool for creating localized heating in, for example, a living cell. In new experiments, researchers at the Niels Bohr Institute have measured the temperature of nano-sized gold particles with extreme precision and have examined their ability to melt the lipid membranes surrounding cells, paving the way for dissolving sick cells. The results have been published in the esteemed journal Nano Letters.

Controlled heating of gold nanoparticles

Copenhagen | Posted on January 18th, 2011

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.

The research was conducted in the Optical Tweezers Group at the Niels Bohr Institute. Optical tweezers are sophisticated instruments, which using an extremely focused laser light can trap and hold gold particles on a nanometer scale. A nanometer is a thousandth of a millimeter and therefore very small. The gold particles are between 60 and 200 nanometers in size.

"The particles can be heated using infrared light from the optical tweezers and by turning the light up and down you can control the heat", explains PhD student in biophysics, Anders Kyrsting, who conducted the research along with his colleagues from the Optical Tweezers group.

But exactly how hot do the extremely small gold particles get? It is important to know the precise temperature in order to have complete control over the situation. The particles are too small to measure directly, so you can instead measure indirectly by their effect.

Anders Kyrsting brought the hot gold particles closer and closer towards an artificial cell membrane comprised of lipids. When quite close the lipids melt and if you know exactly when certain lipids melt you can use this to calculate the temperature of the gold particles. It turns out that the gold particles are able to reach several hundred degrees at a light intensity of less than 1 watt.

Gentle and effective

Having a hot particle means that you have a tool that you can use - a tiny little heat source, which is well-defined. By melting the lipids in a cell membrane the cell will be dissolved - killed. But only that cell.

"The heat decreases so rapidly that at just a radius of a gold particle from the surface, the heat is half the temperature than it is at the surface. That is to say, that a typical cell length away from the particle the heat will have decreased so much that it is harmless", explains Anders Kyrsting.

"The technique can also be used as a tool for changing temperatures in a few microseconds. When the temperature from the surface of a heated gold nanoparticle decreases several hundred degrees per micrometer, it is, for example, possible to have two separate states - a liquid and a more solid form in artificial cell systems consisting of small lipid vesicles. Here the border surface between the two states will be very clear-cut, which is useful if you want to study cell membranes", explains Anders Kyrsting.

####

For more information, please click here

Contacts:
Gertie Skaarup

Copyright © Niels Bohr Institute

If 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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

Possible Futures

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 2016

New lithium-oxygen battery greatly improves energy efficiency, longevity: New chemistry could overcome key drawbacks of lithium-air batteries July 26th, 2016

Academic/Education

The NanoWizard® AFM from JPK is applied for interdisciplinary research at the University of South Australia for applications including smart wound healing and how plants can protect themselves from toxins July 26th, 2016

News from Quorum: The College of New Jersey use the Quorum Cryo-SEM preparation system in a project to study ice crystals in high altitude clouds July 19th, 2016

Leti and Korea Institute of Science and Technology to Explore Collaboration on Advanced Technologies for Digital Era July 14th, 2016

SUNY Poly Celebrates Its 10th Year Exhibiting at SEMICON West with Cutting Edge Developments in Integrated Photonics and Power Electronics July 8th, 2016

Nanomedicine

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

The NanoWizard® AFM from JPK is applied for interdisciplinary research at the University of South Australia for applications including smart wound healing and how plants can protect themselves from toxins July 26th, 2016

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

Announcements

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

Nanobiotechnology

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

New remote-controlled microrobots for medical operations July 23rd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic