Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New paper offers insights into “blinking” phenomenon

Abstract:
A new paper by a team of researchers led by University of Notre Dame physicist Bolizsár Jankó provides an overview of research into one of the few remaining unsolved problems of quantum mechanics.

New paper offers insights into “blinking” phenomenon

Notre Dame, IN | Posted on July 1st, 2008

More than a century ago, at the dawn of modern quantum mechanics, the Nobel Prize-winning physicist Neils Bohr predicted so-called "quantum jumps." He predicted that these jumps would be due to electrons making transitions between discrete energy levels of individual atoms and molecules. Although controversial in Bohr's time, such quantum jumps were experimentally observed, and his prediction verified, in the 1980s. More recently, with the development of single molecule imaging techniques in the early 1990s, it has been possible to observe similar jumps in individual molecules.

Experimentally, these quantum jumps translate to discrete interruptions of the continuous emission from single molecules, revealing a phenomenon known as florescent intermittency or "blinking."

However, while certain instances of blinking can be directly ascribed to Bohr's original quantum jumps, many more cases exist where the observed fluorescence intermittency does not follow his predictions. Specifically, in systems as diverse as fluorescent proteins, single-light harvesting complexes, single organic fluorophores, and, most recently, individual inorganic nanostructures, clear deviations from Bohr's predictions occur.

As a consequence, virtually all know fluorophores, including fluorescent quantum dots and molecules, exhibit unexplainable episodes of intermittent "blinking" in their emission. The underlying quantum mechanical process responsible for this phenomenon is an enduring mystery in modern chemical physics.

In a paper appearing in today's edition of the journal Nature Physics, Jankó and his colleagues present a "progress report" on the research, including their own, that has been aimed at unlocking the mysteries of these fluorescent molecules or flourophores. They hope the paper will help spark further experimental and theoretical activity to solve the mystery of fluorescence intermittency.

Finding the answer could lead to powerful imaging probes that will enable future researchers to better track disease-related molecules within cells.

"Fluorescent molecules could be of fundamental importance in imaging biological systems and monitoring dynamic processes in vivo," Jankó said. "One of the most attractive types of flourophores today are semiconductor nanocrystal quantum dots (NQD). Their small size, brightness, photostability and highly tunable fluorescent color make them vastly superior to organic dyes."

The blinking phenomenon, however, presents a daunting difficulty in using these dots, especially for such applications as single-molecule biological imaging, where a single NQD is used as a fluorescent label.

"The NQD is fluorescent for some time, a so-called ‘on-time,' and then becomes optically inactive, experiencing an ‘off-time,' whereupon it turns on again," Jankó said.

If the blinking process could be controlled, quantum dots could, for example, provide better, more stable, multi-color imaging of cancer cells or provide researchers with real-time images of a viral infection, such HIV, within a cell.

"It is very important to elucidate the origin of this phenomenon and to identify ways to control the blinking process," Jankó said.

Jankó's Notre Dame research group already has taken a strong first step toward understanding the phenomenon through research by group member Masaru Kuno, an assistant professor of chemistry and biochemistry at the University. Kuno has discovered that the on- and off-time intervals of intermittent nanocrystal quantum dots follow a universal power law distribution. This discovery has provided Notre Dame researchers and others with the first hints for developing a deeper insight into the physical mechanism behind the vast range of on- and off-times in the intermittency.

Jankó has received a $1.2 million National Science Foundation Nanoscale Interdisciplinary Research Team (NIRT) grant to help solve the fluorescence intermittency mystery.

####

About University of Notre Dame
The University of Notre Dame, founded in 1842 by Rev. Edward F. Sorin, C.S.C., of the Congregation of Holy Cross, is an independent, national Catholic university located in Notre Dame, Ind., adjacent to the city of South Bend and approximately 90 miles east of Chicago.

For more information, please click here

Contacts:
Boldizsár Jankó
professor of physics
574-631-8049

Copyright © University of Notre Dame

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

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Rice U. lab surprised by ultraflat magnets: Researchers create atom-thick alloys with unanticipated magnetic properties October 13th, 2017

Discoveries

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Announcements

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Quantum Dots/Rods

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

Coupling a nano-trumpet with a quantum dot enables precise position determination July 14th, 2017

Quantum nanoscience

What can be discovered at the junction of physics and chemistry October 6th, 2017

Energy against the current on a quantum scale, without contradicting the laws of physics: A piece of research in which the UPV/EHU-University of the Basque Country has participated confirms that merely observing a flow of energy or particles can change its direction October 6th, 2017

Enhancing the sensing capabilities of diamonds with quantum properties: A simple method can give diamonds the special properties needed for quantum applications such as sensing magnetic fields September 24th, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 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