Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

Self-assembling biomaterial forms nanostructure templates for human tissue formation April 27th, 2015

International research team discovers new mechanism behind malaria progression: Findings provide a new avenue for research in malaria treatment April 27th, 2015

More is less in novel electronic material: Adding electrons actually shrinks the system April 27th, 2015

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Possible Futures

Printing Silicon on Paper, with Lasers April 21st, 2015

A glass fiber that brings light to a standstill: By coupling photons to atoms, light in a glass fiber can be slowed down to the speed of an express train; for a short while it can even be brought to a complete stop April 9th, 2015

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Academic/Education

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Iranian Female Professor Awarded UNESCO Medal in Nanoscience April 20th, 2015

JPK reports on the use of the NanoWizardŽ 3 AFM system at the Hebrew University of Jerusalem April 14th, 2015

UK National Graphene Institute Selects Bruker as Official Partner: World-Leading Graphene Research Facility Purchases Multiple Bruker AFMs April 7th, 2015

Nanomedicine

Self-assembling biomaterial forms nanostructure templates for human tissue formation April 27th, 2015

International research team discovers new mechanism behind malaria progression: Findings provide a new avenue for research in malaria treatment April 27th, 2015

Scientists join forces to reveal the mass and shape of single molecules April 27th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Announcements

Scientists join forces to reveal the mass and shape of single molecules April 27th, 2015

The 16th Trends in Nanotechnology International Conference (TNT 2015) unveils 25 Keynote Speakers: Call for abstracts open April 27th, 2015

Graphenea celebrates fifth anniversary April 27th, 2015

Sensor Designed in Iran Able to Remove Formaldehyde Gas from Environment April 27th, 2015

Nanobiotechnology

Self-assembling biomaterial forms nanostructure templates for human tissue formation April 27th, 2015

Scientists join forces to reveal the mass and shape of single molecules April 27th, 2015

A silver lining: UCSB researchers cradle silver nanoclusters inside synthetic DNA to create a programmed, tunable fluorescent array April 23rd, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

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