Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > DNA and quantum dots: All that glitters is not gold

The NIST team explored the behavior of quantum dots and gold nanoparticles placed in different configurations on small rectangular constructs made of self-assembled DNA (see inset for photograph). Laser light (green) allowed the team to explore changes in the fluorescent lifetime of the quantum dots when close to gold particles of different sizes.

Credit: NIST
The NIST team explored the behavior of quantum dots and gold nanoparticles placed in different configurations on small rectangular constructs made of self-assembled DNA (see inset for photograph). Laser light (green) allowed the team to explore changes in the fluorescent lifetime of the quantum dots when close to gold particles of different sizes.

Credit: NIST

Abstract:
A team of researchers at the National Institute of Standards and Technology (NIST) has shown that by bringing gold nanoparticles close to the dots and using a DNA template to control the distances, the intensity of a quantum dot's fluorescence can be predictably increased or decreased.* This breakthrough opens a potential path to using quantum dots as a component in better photodetectors, chemical sensors and nanoscale lasers.

DNA and quantum dots: All that glitters is not gold

Gaithersburg, MD | Posted on January 25th, 2013

Anyone who has tried to tune a radio knows that moving their hands toward or away from the antenna can improve or ruin the reception. Although the reasons are well understood, controlling this strange effect is difficult, even with hundred-year-old radio technology. Similarly, nanotechnology researchers have been frustrated trying to control the light emitted from quantum dots, which brighten or dim with the proximity of other particles.

The NIST team developed ways to accurately and precisely place different kinds of nanoparticles near each other and to measure the behavior of the resulting nanoscale constructs. Because nanoparticle-based inventions may require multiple types of particles to work together, it is crucial to have reliable methods to assemble them and to understand how they interact.

The researchers looked at two types of nanoparticles, quantum dots, which glow with fluorescent light when illuminated, and gold nanoparticles, which have long been known to enhance the intensity of light around them. The two could work together to make nanoscale sensors built using rectangles of woven DNA strands, formed using a technique called "DNA origami."

These DNA rectangles can be engineered to capture different types of nanoparticles at specific locations with a precision of about one nanometer. Tiny changes in the distance between a quantum dot and a gold nanoparticle near one another on the rectangle cause the quantum dot to glow more or less brightly as it moves away from or toward the gold. Because these small movements can be easily detected by tracking the changes in the quantum dot's brightness, they can be used to reveal, for example, the presence of a particular chemical that is selectively attached to the DNA rectangle. However, getting it to work properly is complicated, says NIST's Alex Liddle.

"A quantum dot is highly sensitive to the distance between it and the gold, as well as the size, number and arrangement of the gold particles," says Liddle, a scientist with the NIST Center for Nanoscale Science and Technology. "These factors can boost its fluorescence, mask it or change how long its glow lasts. We wanted a way to measure these effects, which had never been done before."

Liddle and his colleagues made several groups of DNA rectangles, each with a different configuration of quantum dots and gold particles in a solution. Using a laser as a spotlight, the team was able to follow the movement of individual DNA rectangles in the liquid, and also could detect changes in the fluorescent lifetime of the quantum dots when they were close to gold particles of different sizes. They also showed that they could exactly predict the lifetime of the fluorescence of the quantum dot depending on the size of the nearby gold nanoparticles.

While their tracking technique was time consuming, Liddle says that the strength of their results will enable them to engineer the dots to have a specific desired lifetime. Moreover, the success of their tracking method could lead to better measurement methods.

"Our main goals for the future," he concludes, "are to build better nanoscale sensors using this approach and to develop the metrology necessary to measure their performance."

*S.H. Ko, K. Du and J.A. Liddle.Quantum-dot fluorescence lifetime engineering with DNA origami constructs. Angewandte Chemie (Int. Ed.), 52: 1193-1197. doi: 10.1002/anie.201206253.

####

For more information, please click here

Contacts:
Chad Boutin

301-975-4261

Copyright © National Institute of Standards and Technology (NIST)

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

'Gyroscope' molecules form crystal that's both solid and full of motion: New type of molecular machine designed by UCLA researchers could have wide-ranging applications in technology and science January 16th, 2018

The nanoscopic structure that locks up our genes January 16th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

Nanotube fibers in a jiffy: Rice University lab makes short nanotube samples by hand to dramatically cut production time January 11th, 2018

IBM Breaks Records to Top U.S. Patent List for 25th Consecutive Year: IBM Inventors Receive Record 9,043 Patents in 2017 in Areas such as Artificial Intelligence, Cloud, Blockchain, Cybersecurity and Quantum Computing January 11th, 2018

Imaging

The nanoscopic structure that locks up our genes January 16th, 2018

Silver nanoparticles take spectroscopy to new dimension: A new way of organizing nanostructures has boosted Raman signals by a hundred thousand times to better identify and characterize different molecules January 2nd, 2018

Laboratories

Laboratory Management Web Application Goes Nationwide January 9th, 2018

NRL improves optical efficiency in nanophotonic devices January 4th, 2018

Tweaking quantum dots powers-up double-pane solar windows: Engineered quantum dots could bring down the cost of solar electricity January 2nd, 2018

Govt.-Legislation/Regulation/Funding/Policy

'Gyroscope' molecules form crystal that's both solid and full of motion: New type of molecular machine designed by UCLA researchers could have wide-ranging applications in technology and science January 16th, 2018

The nanoscopic structure that locks up our genes January 16th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

'Decorated' stem cells could offer targeted heart repair January 11th, 2018

Sensors

NRL improves optical efficiency in nanophotonic devices January 4th, 2018

'Quantum material' has shark-like ability to detect small electrical signals December 20th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Leti Will Demonstrate First 3D Anti-Crash Solution for Embedding in Drones: Fitted on a Mass-Market Microcontroller, 360Fusion Software Technology Detects any Dynamic Obstacle and Helps Guide Drones Away from Collisions December 15th, 2017

Discoveries

'Gyroscope' molecules form crystal that's both solid and full of motion: New type of molecular machine designed by UCLA researchers could have wide-ranging applications in technology and science January 16th, 2018

The nanoscopic structure that locks up our genes January 16th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

'Decorated' stem cells could offer targeted heart repair January 11th, 2018

Announcements

'Gyroscope' molecules form crystal that's both solid and full of motion: New type of molecular machine designed by UCLA researchers could have wide-ranging applications in technology and science January 16th, 2018

The nanoscopic structure that locks up our genes January 16th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

'Decorated' stem cells could offer targeted heart repair January 11th, 2018

Quantum Dots/Rods

Tweaking quantum dots powers-up double-pane solar windows: Engineered quantum dots could bring down the cost of solar electricity January 2nd, 2018

Quantum communications bend to our needs: By changing the wavelengths of entangled photons to those used in telecommunications, researchers see quantum technology take a major leap forward September 28th, 2017

Band Gaps, Made to Order: Engineers create atomically thin superlattice materials with precision September 26th, 2017

New approach on research and design for CQD catalysts in World Scientific NANO August 2nd, 2017

Photonics/Optics/Lasers

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

New oxide and semiconductor combination builds new device potential: Researchers integrated oxide two-dimensional electron gases with gallium arsenide and paved the way toward new opto-electrical devices January 10th, 2018

NRL improves optical efficiency in nanophotonic devices January 4th, 2018

Ocean Optics Grows Sales Organization with Executive Appointments: Henry Langston promoted, Christine Stannard joins spectral sensing product developer December 23rd, 2017

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