Featured Research

from universities, journals, and other organizations

New Insights Into Quantum Mechanics: Unlocking Mysteries Of 'Blinking' Phenomena Of Fluorescent Molecules

Date:
July 2, 2008
Source:
University of Notre Dame
Summary:
More than a century ago, at the dawn of modern quantum mechanics, the Nobel Prize-winning physicist Neils Bohr predicted so-called "quantum jumps." More recently, 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."

Experimentally, quantum jumps translate to discrete interruptions of the continuous emission from single molecules, revealing a phenomenon known as florescent intermittency or "blinking."
Credit: Image courtesy of University of Notre Dame

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.

Related Articles


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 the July 1 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.


Story Source:

The above story is based on materials provided by University of Notre Dame. Note: Materials may be edited for content and length.


Cite This Page:

University of Notre Dame. "New Insights Into Quantum Mechanics: Unlocking Mysteries Of 'Blinking' Phenomena Of Fluorescent Molecules." ScienceDaily. ScienceDaily, 2 July 2008. <www.sciencedaily.com/releases/2008/07/080701142504.htm>.
University of Notre Dame. (2008, July 2). New Insights Into Quantum Mechanics: Unlocking Mysteries Of 'Blinking' Phenomena Of Fluorescent Molecules. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2008/07/080701142504.htm
University of Notre Dame. "New Insights Into Quantum Mechanics: Unlocking Mysteries Of 'Blinking' Phenomena Of Fluorescent Molecules." ScienceDaily. www.sciencedaily.com/releases/2008/07/080701142504.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will New A350 Help Airbus Fly?

Will New A350 Help Airbus Fly?

Reuters - Business Video Online (Dec. 22, 2014) — Qatar Airways takes first delivery of Airbus' new A350 passenger jet. As Joel Flynn reports it's the planemaker's response to the Boeing 787 Dreamliner and the culmination of eight years of development. Video provided by Reuters
Powered by NewsLook.com
Man Parachutes Off Lawn Chair Airlifted By Helium Balloons

Man Parachutes Off Lawn Chair Airlifted By Helium Balloons

Buzz60 (Dec. 22, 2014) — A BASE jumper rides a lawn chair, a shotgun, and a giant bunch of helium balloons into the sky in what seems like a country version of the movie 'Up." Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) — A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins