Featured Research

from universities, journals, and other organizations

Researchers Find The "North Pole" Of The Molecular World

Date:
June 22, 2001
Source:
University Of Rochester
Summary:
Researchers have devised a method to determine the alignment of a molecule's axis, the "poles" that govern how a molecule will interact with others. The advancement will help scientists and engineers predict the ways that atoms and molecules exchange energy, possibly enhancing solar energy devices or helping biochemists better understand proteins.

Researchers have devised a method to determine the alignment of a molecule's axis, the "poles" that govern how a molecule will interact with others. The advancement will help scientists and engineers predict the ways that atoms and molecules exchange energy, possibly enhancing solar energy devices or helping biochemists better understand proteins. The research, appearing in the June 4 issue of Physical Review Letters, shows how a tightly-focused laser employing a new kind of polarization can produce valuable images of individual molecules in three dimensions.

Related Articles


The new method takes a snapshot of a phenomenon called the "molecular dipole moment." This "moment" is an axis that runs through the molecule like a north and south pole, along which energy is emitted and absorbed. If two molecules are positioned so that their respective poles align, they are more likely to exchange energy. If they are completely misaligned, then an interaction is more difficult. Someday, researchers hope to control the alignment to direct chemical reactions at the atomic level.

"By imaging the dipole movement of certain molecules we can see exactly how certain chemical reactions happen," says Lukas Novotny, assistant professor of optics at the University of Rochester. "We're working now with biochemists to understand how various proteins in the body form."

Proteins fold when they form, but monitoring their folding is a tricky business that the Rochester team's method can help clarify. To watch the folding process, researchers place two marker molecules at each end of the protein-one marker emits green light when stimulated, and the other emits red. One marker (the green one) is charged with energy so that it emits its light. When the protein folds itself and brings these two markers together like a gymnast touching her toes, the green marker gives some of its energy to the other, which then glows, causing a change in the overall color of light emitted from the protein. Exactly when this energy exchange takes place, however, depends on how far apart the marker molecules are and how their "poles" are oriented. Biochemists will now be able to know exactly what the markers' orientations are, and so know exactly how far the protein has folded when the emitted light changes. This puts a powerful new tool in the hands of scientists investigating cellular processes.

Determining the north pole of an atom required a new class of light polarization, the development of which was pioneered by Thomas Brown, associate professor of optics at the University. Regular light has linear polarization, which means it essentially vibrates within a plane. The molecule-imaging method, however, uses radial polarization, where the vibration moves in several planes radiating outward from the light beam. By converting regular laser light to radial-polarized light and tightly focusing the laser beam, the team can create a tiny electric field that is of equal strength in all three dimensions, thanks to the radial polarization. The team then scans the beam along the molecule in all directions until one of the radial planes lines up with the north or south pole, and the atom absorbs the energy. A slight burst of fluorescence tells the team when they've hit their mark, and they can determine at exactly what angle the pole is oriented.

Novotny sees other applications for molecular dipole moments. "Cells in the body communicate through proteins located in their membranes. During an exchange of information, the shape of the proteins changes. By attaching molecular markers to the protein and monitoring their orientation and position, we should be able to better understand communication between cells." Tracking the dipole moments might also shed light on how cancer cells grow in colonies. Novotny predicts that someday molecular dipole moments may be not just ascertained but controlled, allowing for quick, custom-made molecule alignment, or even data storage, since the orientation of the dipole moment could stand for a one or zero.

Joining Novotny and Brown in the research are postdoctoral research associate Achim Hartschuh and graduate students Michael Beversluis and Kathleen Youngworth of the University. The work was funded by the National Science Foundation.


Story Source:

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


Cite This Page:

University Of Rochester. "Researchers Find The "North Pole" Of The Molecular World." ScienceDaily. ScienceDaily, 22 June 2001. <www.sciencedaily.com/releases/2001/06/010605075137.htm>.
University Of Rochester. (2001, June 22). Researchers Find The "North Pole" Of The Molecular World. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2001/06/010605075137.htm
University Of Rochester. "Researchers Find The "North Pole" Of The Molecular World." ScienceDaily. www.sciencedaily.com/releases/2001/06/010605075137.htm (accessed October 30, 2014).

Share This



More Matter & Energy News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Reuters - Innovations Video Online (Oct. 29, 2014) A Swedish amputee who became the first person to ever receive a brain controlled prosthetic arm is able to manipulate and handle delicate objects with an unprecedented level of dexterity. The device is connected directly to his bone, nerves and muscles, giving him the ability to control it with his thoughts. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Robots Get Funky on the Dance Floor

Robots Get Funky on the Dance Floor

AP (Oct. 29, 2014) Dancing, spinning and fighting robots are showing off their agility at "Robocomp" in Krakow. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Saharan Solar Project to Power Europe

Saharan Solar Project to Power Europe

Reuters - Business Video Online (Oct. 29, 2014) A solar energy project in the Tunisian Sahara aims to generate enough clean energy by 2018 to power two million European homes. Matt Stock reports. Video provided by Reuters
Powered by NewsLook.com
Lowe's Testing Robot Sales Assistants in California Store

Lowe's Testing Robot Sales Assistants in California Store

Buzz60 (Oct. 29, 2014) Lowe’s is testing out what it’s describing as a robotic shopping assistant in one of its Orchard Supply Hardware Stores in California. Jen Markham explains. Video provided by Buzz60
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