Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Twinkle, twinkle, quantum dot -- new particles can change colors and tag molecules

Researchers at Ohio State University have invented fluorescent nano-particles that change color to tag molecules under the microscope. This series of photos shows a particle changing from red to green -- and, at the 89-second mark, to yellow -- over the course of two minutes.

Credit: Image by Gang Ruan, courtesy of Ohio State University.
Researchers at Ohio State University have invented fluorescent nano-particles that change color to tag molecules under the microscope. This series of photos shows a particle changing from red to green -- and, at the 89-second mark, to yellow -- over the course of two minutes.

Credit: Image by Gang Ruan, courtesy of Ohio State University.

Abstract:
Engineers at Ohio State University have invented a new kind of nano-particle that shines in different colors to tag molecules in biomedical tests.

Twinkle, twinkle, quantum dot -- new particles can change colors and tag molecules

Columbus, OH | Posted on March 28th, 2011

These tiny plastic nano-particles are stuffed with even tinier bits of electronics called quantum dots. Like little traffic lights, the particles glow brightly in red, yellow, or green, so researchers can easily track molecules under a microscope.

This is the first time anyone has created fluorescent nano-particles that can change colors continuously.

Jessica Winter, assistant professor of chemical and biomolecular engineering and biomedical engineering, and research scientist Gang Ruan describe their patent-pending technology in the online edition of the journal Nano Letters.

Researchers routinely tag molecules with fluorescent materials in order to see them under the microscope. Unlike the more common fluorescent molecules, quantum dots shine very brightly, and could illuminate chemical reactions especially well, allowing researchers to see the inner workings of living cells.

A bottleneck to combating major diseases like cancer is the lack of molecular or cellular-level understanding of biological processes, the engineers explained.

"These new nanoparticles could be a great addition to the arsenal of biomedical engineers who are trying to find the roots of diseases," Ruan said.

"We can tailor these particles to tag particular molecules, and use the colors to track processes that we wouldn't otherwise be able to," he continued. "Also, this work could be groundbreaking for the field of nanotechnology as a whole, because it solves two seemingly irreconcilable problems with using quantum dots."

Quantum dots are pieces of semiconductor that measure only a few nanometers, or billionths of a meter, across. They are not visible to the naked eye, but when light shines on them, they absorb energy and begin to glow. That's what makes them good tags for molecules.

Due to quantum mechanical effects, quantum dots "twinkle" - they blink on and off at random moments. When many dots come together, however, their random blinking is less noticeable. So, large clusters of quantum dots appear to glow with a steady light.

Blinking has been a problem for researchers, because it breaks up the trajectory of a moving particle or tagged molecule that they are trying to follow. Yet, blinking is also beneficial, because when dots come together and the blinking disappears, researchers know for certain that tagged molecules have aggregated.

"Blinking is good and bad," Ruan explained. "But one day we realized that we could use the 'good' and avoid the 'bad' at the same time, by grouping a few quantum dots of different colors together inside a micelle."

A micelle is a nano-sized spherical container, and while micelles are useful for laboratory experiments, they are easily found in household detergents - soap forms micelles that capture oils in water. Ruan created micelles using polymers, with different combinations of red and green quantum dots inside them.

In tests, he confirmed that the micelles appeared to glow steadily. Those stuffed with only red quantum dots glowed red, and those stuffed with green glowed green. But those he stuffed with red and green dots alternated from red to green to yellow.

The color change happens when one or another dot blinks inside the micelle. When a red dot blinks off and the green blinks on, the micelle glows green. When the green blinks off and the red blinks on, the micelle glows red. If both are lit up, the micelle glows yellow.

The yellow color is due to our eyes' perception of light. The process is the same as when a red pixel and green pixel appear close together on a television or computer screen: our eyes see yellow.

Nobody can control when color changes happen inside individual micelles. But because the particles glow continuously, researchers can use them to track tagged molecules continuously. They can also monitor color changes to detect when molecules come together.

Winter and Ruan said that the particles could also be used in fluid mechanics research - specifically, micro-fluidics. Researchers who are developing tiny medical devices with fluid separation channels could use quantum dots to follow the fluid's path.

The same Ohio State research team is also developing magnetic particles to enhance medical imaging of cancer, and it may be possible to combine magnetism with the quantum dot technology for different kinds of imaging. But before the particles would be safe to use in the body, they would have to be made of biocompatible materials. Carbon-based nanomaterials are one possible option.

In the meantime, Winter and Ruan are going to continue developing the color-changing quantum dot particles for studies of cells and molecules under the microscope. They are also going to explore what happens when quantum dots of another color - for instance, blue - are added to the mix.

The university will look to license the technology for industry, and Winter and Ruan have created a Web site for the technologies they are developing: nanoforneuro.com.

This research was supported by the National Science Foundation, an endowment from the William G. Lowrie family to the Department of Chemical and Biomolecular Engineering, and the Center for Emergent Materials at Ohio State.

####

For more information, please click here

Contacts:
Jessica Winter


Gang Ruan


Written by
Pam Frost Gorder
(614) 292-9475

Copyright © Ohio State 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

Imaging

National Synchrotron Light Source II Achieves 'First Light' October 23rd, 2014

News and information

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

MEMS & Sensors Technology Showcase: Finalists Announced for MEMS Executive Congress US 2014 October 23rd, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

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

Govt.-Legislation/Regulation/Funding/Policy

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Brookhaven Lab Launches Computational Science Initiative:Leveraging computational science expertise and investments across the Laboratory to tackle "big data" challenges October 22nd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

Discoveries

Iranian Scientists Apply Nanotechnology to Produce Surgery Suture October 23rd, 2014

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Announcements

Nanoparticle technology triples the production of biogas October 23rd, 2014

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

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

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

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

Quantum Dots/Rods

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

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

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