Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Nano imagining takes turn for the better

An electron microscope photo from the new paper shows nanorods about 75 nanometers long and 25 nanometers wide on a glass slide at 90-degree angles to each other. An adjacent photothermal image shows them as pixilated smudges.
An electron microscope photo from the new paper shows nanorods about 75 nanometers long and 25 nanometers wide on a glass slide at 90-degree angles to each other. An adjacent photothermal image shows them as pixilated smudges.

Abstract:
Photothermal technique provides new way to track nanoparticles

Nano imagining takes turn for the better

Houston, TX | Posted on February 3rd, 2010

Stephan Link wants to understand how nanomaterials align, and his lab's latest work is a step in the right direction.

Link's Rice University group has found a way to use gold nanorods as orientation sensors by combining their plasmonic properties with polarization imaging techniques.

That may make it possible to see and perhaps track single nanoparticles over long periods. It would give researchers new information about materials, including living systems, that incorporate them.

"With a spherical particle, you don't have any information about how it's oriented," said Link, an assistant professor of chemistry and electrical and computer engineering at Rice. "We wanted to see if we could determine the orientation of the nanorods, and eventually we'd like to be able to measure the orientation of the environment they're in. We think this technique could be really useful for that."

Link, primary author Wei-Shun Chang, a Rice research scientist, and their collaborators reported their results this week in the online edition of the Proceedings of the National Academy of Sciences.

Seeing a single nanoparticle is nothing new. A scanning tunneling microscope (STM) can capture images of particles down to a few nanometers; particles tagged with fluorescent molecules can be seen for as long as the fluorophores are active. Link used this latter method to show nanocars rolling at room temperature last year.

But there are problems with each of those techniques. STMs see nanotubes or quantum dots just fine as long as they're more or less isolated on a conductive surface. But in the wild, the particles would get lost amid the clutter of everything else the microscope sees. And while fluorophores can help pick particles out of the crowd, they can deteriorate in as little as 30 seconds, which limits their usefulness.

Gold nanorods can be "lit up" at will. Lasers at particular wavelengths excite surface plasmons that absorb the energy and emit a heat signature that can be detected by a probe laser. Because plasmons are highly polarized along a nanorod's length, reading the signal while turning the polarization of the laser tells researchers precisely how the rod is oriented.

An electron microscope photo from the new paper shows nanorods about 75 nanometers long and 25 nanometers wide on a glass slide at 90-degree angles to each other. An adjacent photothermal image shows them as pixilated smudges. The smudges are strongest when the laser polarization aligns lengthwise with the nanorods, but they disappear when the laser polarization and rods are 90 degrees out of phase.

"With plasmonics, you always have two properties: absorption and scattering," Link said. "Depending on the size, one or the other dominates. What's unique is that it's now possible to do both on the same structure or do it individually -- so we can only measure absorption or only measure scattering."

Nanorods much smaller than 50 nanometers are not detectable by some scattering methods, Link said, but photothermal detection should work with metallic particles as small as five nanometers; this makes them useful for biological applications. "These gold nanorods are biocompatible. They are not toxic to cells," said Chang, noting their similarity to gold nanoshells currently in human cancer therapy trials based on research by Rice scientists Naomi Halas and Jennifer West.

"Our work is more geared to the fundamentals," Link said of the basic nature of his group's research. "Maybe we can optimize the conditions, and then a physician or somebody who's engineering a probe can take it from there.

"Our place is a little further down the chain of development. I'm happy with that."

Co-authors of the paper are Rice graduate students Ji Won Ha and Liane Slaughter. The Robert A. Welch Foundation and 3M supported the work.

View the paper at www.pnas.org/content/early/2010/01/25/0910127107.abstract.

####

About Rice University
Located in Houston, Rice University is consistently ranked one of America's best teaching and research universities. Known for its "unconventional wisdom," Rice is distinguished by its: size -- 3,102 undergraduates and 2,237 graduate students; selectivity -- 12 applicants for each place in the freshman class; resources -- an undergraduate student-to-faculty ratio of 5-to-1; sixth largest endowment per student among American private research universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work.

For more information, please click here

Contacts:
David Ruth
Associate Director for National Media Relations
Rice University
Direct: 713-348-6327
Cell: 612-702-9473

Copyright © Rice University

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

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Nanotubes/Buckyballs

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

NTU develops ultra-fast charging batteries that last 20 years October 14th, 2014

Fast, cheap nanomanufacturing: Arrays of tiny conical tips that eject ionized materials could fabricate nanoscale devices cheaply October 4th, 2014

Nanomedicine

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Non-Toxic Nanocatalysts Open New Window for Significant Decrease in Reaction Process October 19th, 2014

European Commission opens the gate towards the implementation of Nanomedicine Translation Hub October 16th, 2014

Tuning light to kill deep cancer tumors: Nanoparticles developed at UMass Medical School advance potential clinical application for photodynamic therapy October 15th, 2014

Sensors

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Graphenea opens US branch October 16th, 2014

IRLYNX and CEA-Leti to Streamline New CMOS-based Infrared Sensing Modules Dedicated to Human-activities Characterization October 15th, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Discoveries

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Announcements

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Design of micro and nanoparticles to improve treatments for Alzheimers and Parkinsons: At the Faculty of Pharmacy of the UPV/EHU-University of the Basque Country encapsulation techniques are being developed to deliver correctly and effectively certain drugs October 20th, 2014

Physicists build reversible laser tractor beam October 20th, 2014

Removal of Limitations of Composites at Superheat Temperatures October 20th, 2014

Tools

New Grand ARM Transmission Electron Microscope Offers Highest Commercially-Available Atomic Resolution of 63 Picometers October 17th, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Nanotronics Imaging Releases nSPECŪ 3D, Powerful Microscope That Captures 3D Images at Nanoscale, in Lightning Speed: Company Unveils Design at American Chemical Society 2014 International Elastomer Conference October 14th, 2014

Unique catalysts for hydrogen fuel cells synthesized in ordinary kitchen microwave oven October 14th, 2014

Quantum Dots/Rods

QD Vision Wins Prestigious Presidential Green Chemistry Challenge Award from the U.S. Environmental Protection Agency October 16th, 2014

Ultrafast remote switching of light emission October 2nd, 2014

Platinum meets its match in quantum dots from coal: Rice University's cheap hybrid outperforms rare metal as fuel-cell catalyst October 1st, 2014

University of Electro-Communications research: High density quantum dots for powerful solar cells September 25th, 2014

Nanobiotechnology

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Scientists Map Key Moment in Assembly of DNA-Splitting Molecular Machine: Crucial steps and surprising structures revealed in the genesis of the enzyme that divides the DNA double helix during cell replication October 15th, 2014

DNA nano-foundries cast custom-shaped metal nanoparticles: DNA's programmable assembly is leveraged to form precise 3D nanomaterials for disease detection, environmental testing, electronics and beyond October 10th, 2014

Charged graphene gives DNA a stage to perform molecular gymnastics October 9th, 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