Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Look at Mie!

From left, Rice graduate students Sergio Dominguez-Medina, Liane Slaughter and Alexei Tcherniak, co-authors (with Stephan Link and Ji Won Ha) of a new paper investigating the plasmonic properties of nanoparticles as they relate to a century-old theory. Courtesy Jeff Fitlow.
From left, Rice graduate students Sergio Dominguez-Medina, Liane Slaughter and Alexei Tcherniak, co-authors (with Stephan Link and Ji Won Ha) of a new paper investigating the plasmonic properties of nanoparticles as they relate to a century-old theory. Courtesy Jeff Fitlow.

Abstract:
Rice team tests century-old calculations

By Mike Williams, Rice News Staff

Look at Mie!

Houston, TX | Posted on March 13th, 2010

Calculations are fine, but seeing is believing. That's the thought behind a new paper by Rice University students who decided to put to the test calculations made more than a century ago.

In 1908, the German physicist Gustav Mie came up with an elegant set of equations to describe the interaction of electromagnetic waves with a spherical metal particle. The theory has been a touchstone ever since for researchers seeking to quantify how nanoscale plasmonic particles scatter radiation.

"The Mie theory is used extensively whenever you deal with nanoparticles and their optical properties," said Alexei Tcherniak, a Rice graduate student and primary author of the new paper in the online edition of Nano Letters this month. "That's the foundation of every calculation."

Tcherniak and Stephan Link, a Rice assistant professor of chemistry and electrical and computer engineering, co-authored the paper with former graduate student Ji Won Ha and current Rice graduate students Liane Slaughter and Sergio Dominguez-Medina.

Better characterization of single nanoparticles is important to researchers pursuing microscopic optical sensors, subwavelength "super lenses," catalysis and photothermal cancer therapies that use nanoparticles.

"Since technology is moving toward single-particle detection, we wanted to see whether Mie's predictions would hold," Tcherniak said. "Average properties fall exactly on the predictions of Mie theory. But we show that individual particles deviate quite a bit."

Particles that differ in size can return similar signals because they vary in shape and orientation on the substrate, with which they also interact. Mie's theory, developed for spherical particles in solution long before the advent of single-particle spectroscopy, did not consider these factors.

The project began as a sideline in the students' attempt to track single nanoparticles in solution. It became their primary focus when they realized the scope of the task, which involved analyzing five sets of gold particles ranging from 51 to 237 nanometers wide - the "biologically relevant" sizes, Tcherniak explained.

Each set of particles was photographed with a scanning electron microscope and then analyzed for its absorption and scattering properties via single-particle photothermal imaging and laser dark-field scattering.

It was tedious, they admitted.

"When you need to find a particle 50 nanometers across on a sample that is 5-by-5 millimeters, you're looking for a needle in a haystack," Tcherniak said. Slaughter and Dominguez-Medina nodded in agreement and recalled a summer of long days categorizing hundreds of particles -- enough "to get all those points on the graph."

They used a couple of strategies to locate particles. One was to put micron-scale grid coordinates on the glass slide containing nanoparticle samples. "That let us know roughly where they were," Tcherniak said.

Another involved applying a bit of astronomy to their microscopy. They found themselves looking for "constellations" in the patterns of specks. "We started saying, 'Oh, that looks like a nose. Do we have a nose anywhere else?'" Slaughter said. "We were so tired; the names might not have been very good."

But their results are.

"Mie theory was around long before anyone knew about nanoparticles, so it's a neat thing to be able to test it," said Link of his students' work. "This is important because they really put together the building blocks that will enable scientists to look at more complex structures. This was not an easy job."

The National Science Foundation, the Robert A. Welch Foundation and 3M supported the research.


####

About Rice University
Rice has from its inception been dedicated to three missions: educating and preparing outstanding students for diverse careers and lives; contributing to the advancement of knowledge across a wide range of fields; and being of service to our city, our state, our nation, and our world. The Call to Conversation posed the question whether our current mission statement fully encompassed our ambitions, particularly our commitment as a research university to creating new knowledge and our obligation to train future leaders across a range of endeavors. It states: “The mission of Rice University, shaped largely by its founder and the first president, is to provide an unsurpassed undergraduate education in science, engineering, the arts, humanities, and social sciences; to produce internationally distinguished scholarship and research and excellent graduate education in carefully focused areas; to ensure that such an education remains affordable; to maintain the distinctive character of a community of learning that is relatively small in scale; and to serve the continuing educational needs of the larger community.”

For more information, please click here

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

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Govt.-Legislation/Regulation/Funding/Policy

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

'Electronic skin' could improve early breast cancer detection October 29th, 2014

Academic/Education

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Raytheon, UMass Lowell open on-campus research institute: Industry leader’s researchers to collaborate with faculty, students to move key technologies forward through first-of-its-kind partnership October 11th, 2014

SUNY Colleges of Nanoscale Science and Engineering and National Institute for Occupational Safety and Health Announce Expanded Partnership October 2nd, 2014

Nanomedicine

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

'Electronic skin' could improve early breast cancer detection October 29th, 2014

Announcements

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Tools

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

A new cheap and efficient method to improve SERS, an ultra-sensitive chemical detection technique October 28th, 2014

New Compact SIMS at 61st AVS | Visit us on Booth 311 October 28th, 2014

New nanodevice to improve cancer treatment monitoring October 27th, 2014

Nanobiotechnology

Tiny carbon nanotube pores make big impact October 29th, 2014

Molecular beacons shine light on how cells 'crawl' October 27th, 2014

Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future: DNA-based programmable circuits could be more sophisticated, cheaper and simpler to make October 27th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 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