Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

DNA and Quantum Dots: All That Glitters is Not Gold

Published: Thursday, February 07, 2013
Last Updated: Wednesday, January 30, 2013
Bookmark and Share
Researchers have shown that 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. 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."


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More Than 5,000+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

NIST, Stanford Partner on Metrology Initiative
NIST and Stanford University have announced that they are embarking on a long-term partnership to develop the measurement capabilities central to research, innovation and commercialization in a budding bio-economy of products and services in sectors ranging from health care to energy to electronics.
Monday, May 23, 2016
Identifying Vietnamese Wartime Remains
Mike Coble presented latest methods for analyzing DNA from human remains in Hanoi.
Friday, May 20, 2016
Need for Better Characterized Genomes for Clinical Sequencing
A new study that assesses the accuracy of modern human-genome-sequencing technologies found that some medically significant portions of an individual’s DNA blueprint are situated in complex, hard-to-analyze regions that are currently prone to systematic errors.
Thursday, March 03, 2016
Vaccine Fridge Field Study ‘Opens Doors’ to New Standards
Recipients of an annual flu shot may be surprised to learn that there is currently no official standard for vaccine storage equipment in clinics, pharmacies, and other health providers’ offices – a potential problem, since vaccines need to be kept within strict temperature limits to remain viable.
Wednesday, February 24, 2016
Portable Kit Can Recover Traces of Chemical Evidence
A chemist at the National Institute of Standards and Technology (NIST) has developed a portable version of his method for recovering trace chemicals such as environmental pollutants and forensic evidence including secret graves and arson fire debris.
Wednesday, January 13, 2016
Forensic Facial Examiners Can Be Near Perfect
In what might be the first face-off of its kind, trained forensics examiners from the FBI and law enforcement agencies worldwide were far more accurate in identifying faces in photographs than nonexperts and even computers.
Wednesday, September 30, 2015
Contactless Fingerprint Technology is Coming
Quickly moving through security checkpoints by showing your hand to a scanner seems straight out of science fiction, but NIST is working with industry to bring fast, touchless fingerprint readers out of the lab and into the marketplace.
Tuesday, September 08, 2015
Determining the Age of Fingerprints
Watch the imprint of a tire track in soft mud, and it will slowly blur, the ridges of the pattern gradually flowing into the valleys. Researchers have tested the theory that a similar effect could be used to give forensic scientists a way to date fingerprints.
Wednesday, August 26, 2015
New Members of U.S National Commission on Forensic Science Announced
The U.S. Department of Justice (DOJ) and the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) today announced six appointments to the National Commission on Forensic Science.
Friday, August 07, 2015
Giving Cancer a Deadly Fever
Heat may be the key to killing certain types of cancer, and new research has yielded unexpected results that should help optimize the design of magnetic nanoparticles that can be used to deliver heat directly to cancerous tumors.
Thursday, June 18, 2015
Center for Improving Statistical Analysis of Forensic Evidence
The U.S. Commerce Department’s National Institute of Standards and Technology has awarded Iowa State University up to $20 million over five years to establish a Forensic Science Center of Excellence focused on pattern and digital evidence.
Tuesday, June 09, 2015
Measuring Volumes of Key 'Lab on a Chip' Components
NIST found a combination of techniques to effectively measure microfluidic channels, achieving an accuracy of within 5 percent for both a channel's depth and its bottom's width.
Wednesday, April 22, 2015
NMR ‘Fingerprinting’ for Monoclonal Antibodies
Study by NIST researchers shows the use of NMR spectroscopy for measuring the structural congfiguration of monoclonal antibodies.
Thursday, April 16, 2015
Ultra-enriched Silicon Paves the Road to Quantum Computing
Using a relatively straightforward technique, a team of NIST researchers has created what may be the most highly enriched silicon currently being produced.
Wednesday, August 13, 2014
NIST, County Crime Lab Team Up on Ballistics Research
Partnership will contribute to a collection of topographic data from thousands of fired bullets and cartridge cases.
Tuesday, August 12, 2014
Scientific News
Point of Care Diagnostics - A Cautious Revolution
Advances in molecular biology, coupled with the miniaturization and improved sensitivity of assays and devices in general, have enabled a new wave of point-of-care (POC) or “bedside” diagnostics.
Mass Spec Technology Drives Innovation Across the Biopharma Workflow
With greater resolving power, analytical speed, and accuracy, new mass spectrometry technology and techniques are infiltrating the biopharmaceuticals workflow.
One Step Closer to Precision Medicine for Chronic Lung Disease Sufferers
A study led by University of North Carolina at Chapel Hill, and National Jewish Health, has provided evidence of links between SNPs and known COPD blood protein biomarkers.
Blood Pressure Drug May Boost Effectiveness of Lung Cancer Treatment
Researchers at Imperial College London have suggested that the blood pressure drug may make a type of lung cancer treatment more effective.
Insight into Eye Diseases
Scientists recreate zebrafish cell regeneration from retinal stem cells in mice.
New Discovery May Benefit Farmers Worldwide
Scientists have shown how a crop-microbe 'team' protect against fungal infection.
Antibodies Paving the Way to HIV Vaccine
Researchers uncover factors responsible for the formation of broadly neutralizing HIV antibodies in humans.
Designing Drugs with a Whole New Toolbox
Researchers develop methods to design small, targeted proteins with shapes not found in nature.
Protein Studies Discover Molecular Secrets
Two protein studies have mapped proteins that reveal the secrets to recycling carbon and healing cells.
Tapping Evolution to Improve Biotech Products
Researchers show how 'ancestral sequence reconstruction' can be used to guide engineering of a blood clotting protein.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,000+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!