Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Organometallics welcomes new editor-in-chief: Paul Chirik, Ph.D. July 22nd, 2014

The Hiden EQP Plasma Diagnostic with on-board MCA July 22nd, 2014

Iran to Hold 3rd Int'l Forum on Nanotechnology Economy July 22nd, 2014

Nanometrics Announces Upcoming Investor Events July 22nd, 2014

Possible Futures

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

Academic/Education

Haydale Announces Collaboration Agreement with Swansea University’s Welsh Centre for Printing and Coatings (WCPC) July 12th, 2014

STFC takes delivery of the 100th Hitachi Tabletop SEM in the UK July 3rd, 2014

Innovation Management and the Emergence of the Nanobiotechnology Industry July 1st, 2014

Albany NanoCollege Faculty Member Selected as Editor-in-Chief of the Prestigious Journal of Electronic Materials July 1st, 2014

Nanomedicine

Researchers create vaccine for dust-mite allergies Main Page Content: Vaccine reduced lung inflammation to allergens in lab and animal tests July 22nd, 2014

NIST shows ultrasonically propelled nanorods spin dizzyingly fast July 22nd, 2014

SentiMag® Now Available in Australia and New Zealand July 21st, 2014

More than glitter: Scientists explain how gold nanoparticles easily penetrate cells, making them useful for delivering drugs July 21st, 2014

Announcements

Nanometrics Announces Upcoming Investor Events July 22nd, 2014

Bruker Awarded Fourth PeakForce Tapping Patent: AFM Mode Uniquely Combines Highest Resolution Imaging and Material Property Mapping July 22nd, 2014

NIST shows ultrasonically propelled nanorods spin dizzyingly fast July 22nd, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Nanobiotechnology

Production of Non-Virus Nanocarriers with Highest Amount of Gene Delivery July 17th, 2014

Physicists Use Computer Models to Reveal Quantum Effects in Biological Oxygen Transport: The team solved a long-standing question by explaining why oxygen – and not deadly carbon monoxide – preferably binds to the proteins that transport it around the body. July 17th, 2014

Tiny DNA pyramids enter bacteria easily -- and deliver a deadly payload July 9th, 2014

Artificial cilia: Scientists from Kiel University develop nano-structured transportation system July 4th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE