Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Nanoparticles Increase Intensity of Quantum Dots' Glow

Photoluminescence enhancement is demonstrated at the single molecule level for two-particle systems composed of a quantum dot (Qdot) and gold nanoparticle (AuNP) linked by double stranded DNA (dsDNA) when optically excited with wavelengths within the surface plasmon resonance range of the gold nanoparticle.
Photoluminescence enhancement is demonstrated at the single molecule level for two-particle systems composed of a quantum dot (Qdot) and gold nanoparticle (AuNP) linked by double stranded DNA (dsDNA) when optically excited with wavelengths within the surface plasmon resonance range of the gold nanoparticle.

Abstract:
Demonstration of precision DNA-based nanoassembly method could lead to advances in solar cells, optoelectronics, and biosensors

Nanoparticles Increase Intensity of Quantum Dots' Glow

Upton, NY | Posted on July 26th, 2010

By linking individual semiconductor quantum dots with gold nanoparticles, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have demonstrated the ability to enhance the intensity of light emitted by individual quantum dots by up to 20 times. The precision method for making the light-emitting particle clusters published online July 26, 2010 in the journal ChemComm will greatly advance scientists' ability to study and modify the optical properties of quantum dots, and could eventually lead to improved solar energy conversion devices, light-controlled electronics, and biosensors.

"Quantum dots tiny crystals of semiconductor materials that fluoresce, or emit light, in response to photoexcitation have enormous potential for use in a wide range of fields from solar energy conversion to computing and medicine," said Mircea Cotlet, a physical chemist at Brookhaven's Center for Functional Nanomaterials (CFN) and lead author on the current study. "But many factors can influence the light they emit, and it's hard to sort out the contributions of these factors in large samples due to the inherent ensemble averaging. Building single-molecule structures at the CFN seemed the ideal way to tease out these effects."

The Brookhaven team recently developed a precision technique for building such nano-sized structures using short strands of DNA as a highly specific "glue" to link particles together.

"DNA consists of two strands with complementary pairings of bases that stick together in only one way," explained Oleg Gang, leader of the team that developed the technique. "By varying the length of the individual strands and attaching complementary pieces to the particles we want to join, and anchoring the whole process on an assembly surface, we can precisely control the construction of individual nanoclusters."

In the current study, the team used this multi-step process to attach semiconductive quantum dots to gold nanoparticles. Metallic materials are known to affect the optical properties of quantum dots, either by enhancing or inhibiting photoluminescence, depending on a range of factors including the size and shape of the materials, the distance between them, and the wavelength of light used to induce photoexcitation.

The precision assembly technique allowed the scientists to control the size, shape, and distance factors to a high degree of precision and test the effect of wavelength in isolation. They specifically chose two wavelengths to test: one close to the so-called "plasmon resonance" of the gold nanoparticles that is, a wavelength that induces a collective oscillation of the material's conductive electrons, leading to strong absorption of light at that wavelength and one outside this range.

The wavelength within the plasmon resonance range enhanced photoluminescence approximately four-fold when compared with the luminescence achieved by the wavelength outside the plasmon resonance range. When compared with the photoluminescence of individual quantum dots not linked to gold nanoparticles, the resonant wavelength enhanced photoluminescence of the gold-linked quantum dots by an order of magnitude.

"This ability to control the excitonic properties in plasmonic fluorescent quantum dots is essential to the development of devices such as solar cells, light emitting diodes, or optical circuits and might improve the sensitivity of quantum-dot based biosensing assays," Cotlet said.

In addition to Mircea Cotlet and Oleg Gang from Brookhaven, Mathew Maye (now at Syracuse University) contributed to this work. The research was performed at the Center for Functional Nanomaterials at Brookhaven National Laboratory and was supported by the Office of Science of the U.S. Department of Energy.

The Center for Functional Nanomaterials at BNL is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale that are supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories.

Related Links

*DNA-Based Assembly Line for Precision Nano-Cluster Construction:

www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=921

BNL's CFN: www.bnl.gov/cfn/
DOE NSRCs: nano.energy.gov

####

About Brookhaven National Laboratory
One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

For more information, please click here

Contacts:
Karen McNulty Walsh
(631) 344-8350

Peter Genzer
(631) 344-3174

Copyright © Brookhaven National Laboratory

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

A nano-roundabout for light December 10th, 2016

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Possible Futures

A nano-roundabout for light December 10th, 2016

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Sensors

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Tip-assisted chemistry enables chemical reactions at femtoliter scale November 16th, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Announcements

A nano-roundabout for light December 10th, 2016

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Chemical trickery corrals 'hyperactive' metal-oxide cluster December 8th, 2016

Quantum Dots/Rods

Trickling electrons: Close to absolute zero, the particles exhibit their quantum nature November 10th, 2016

Notre Dame researchers find transition point in semiconductor nanomaterials September 6th, 2016

Quantum dots with impermeable shell: A powerful tool for nanoengineering August 12th, 2016

Diamond-based light sources will lay a foundation for quantum communications of the future: Electrified quantum diamond can become the heart of quantum networks and computers of the future August 7th, 2016

Photonics/Optics/Lasers

A nano-roundabout for light December 10th, 2016

ANU invention to inspire new night-vision specs December 7th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Controlled electron pulses November 30th, 2016

Solar/Photovoltaic

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Throwing new light on printed organic solar cells December 1st, 2016

Physics, photosynthesis and solar cells: Researchers combine quantum physics and photosynthesis to make discovery that could lead to highly efficient, green solar cells November 30th, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

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