Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Solid-state proteins maximize the intensity of fluorescent-protein-based lasers
by Staff Writers
Boston MA (SPX) Dec 09, 2014


Molecules of green and red fluorescent proteins, which self-assemble into ring-shaped structures under the right conditions, can be stimulated to emit laser light. Image courtesy Massachusetts General Hospital/University of St. Andrews.

The same research team that developed the first laser based on a living cell has shown that use of fluorescent proteins in a solid form rather than in solution greatly increases the intensity of light produced, an accomplishment that takes advantage of natural protein structures surrounding the light-emitting portions of the protein molecules.

The findings from investigators Seok Hyun Yun, PhD, of the Wellman Center for Photomedicine at Massachusetts General Hospital and Malte Gather, PhD, of the University of St. Andrews in the U.K. appear in the online journal Nature Communications.

"We found that the size and shape of fluorescent proteins are such that their brightness is at the maximum when they are in their most concentrated form," says Yun.

"It is almost as if, through millions of years of biological evolution, Nature optimized these proteins for maximal brightness. Now we have harnessed this property to develop several miniature solid-state lasers."

"Beyond directly using biologically produced fluorescent proteins, studying how they manage to generate light so efficiently at high concentration can guide the design of future, more efficient synthetic materials," adds Gather.

In a 2011 paper published in Nature Photonics, Yun and Gather described using a single cell genetically engineered to express green fluorescent protein (GFP) to amplify the light particles called photons into brief pulses of laser light. Within living cells, fluorescent protein molecules are surrounded by water molecules and other proteins, so their concentration is limited.

The current study was designed to investigate the development of a laser based on fluorescent proteins in a solid state, which would be easier to incorporate into other devices.

The portion of a fluorescent protein molecule that actually emits light - called a fluorophore - is enclosed in a cylindrical protein structure that keeps the fluorophores of adjacent molecules from getting too close to each other, which would reduce the amount of light lost to a phenomenon called quenching.

To investigate their hypothesis that these structural features prevent quenching in naturally occurring fluorescent proteins, even at the highest concentrations, the researchers measured the intensity of light emitted by GFP solutions of varying concentrations and by a thin film of dried GFP, and comparing those results with the light produced by an artificial fluorescent dye.

While at lower concentrations increasing the levels of both GFP and the dye produced increasing fluorescence, at a certain point the amount of light emitted by the artificial dye began to drop off until no light was detectable from the solid form of the dye.

In contrast, the fluorescence of GFP continued to intensify with higher concentrations and maximum brightness was achieved by the solid form, supporting the theory that the fluorophores of GFP and other natural proteins are protected against quenching.

With this evidence that a solid form of GFP produces the brightest light, the investigators first constructed a laser device in which a thin film of dried GFP is sandwiched between two highly reflective mirrors. Compared with devices utilizing lower concentrations of GFP in solution, the solid-state GFP laser required 10 times less excitation energy to start lasing.

Another device took advantage of the "coffee-stain effect," in which material dissolved in solution is deposited in a ring around the edge of a drop as it dries. The team's experiments revealed that the light emitted by the protein molecules within microscopic rings formed by dried droplets of a fluorescent protein is amplified as it circulates around the ring, leading to production of laser light.

Putting rings of different types of fluorescent proteins close together enabled the investigators to realize multi-color laser emission. Changes in the humidity of the environment of the protein rings changes the intensity of light emitted, indicating that devices based on the effect could be used as sensors.

"This GFP ring laser is the first laser made entirely of proteins," says Yun. "In the future biocompatible lasers may be implanted in the body or embedded inside tissues to enable optical sensing of the molecular and physical environment, stimulation of cells or activation of light-sensitive drugs."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Massachusetts General Hospital
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








TECH SPACE
Creating Bright X-Ray Pulses in the Laser Lab
Vienna, Austria (SPX) Nov 12, 2014
X-rays are widely used in medicine and in materials science. To take a picture of a broken bone, it is enough to create a continuous flux of X-ray photons, but in order to study time-dependent phenomena on very short timescales, short X-ray pulses are required. One possibility to create short hard X-ray pulses is hitting a metal target with laser pulses. The laser rips electrons out of the ... read more


TECH SPACE
Carnegie Mellon Unveils Lunar Rover "Andy"

Why we should mine the moon

Young Volcanoes on the Moon

Russia Preparing Joint Moon Exploration Agreement With EU

TECH SPACE
Flash-Memory Reformat Planned

Mars mountain may have arisen from lake sediments: NASA

Curiosity finds clues to how water helped shape Mars

China's ardor for a red planet

TECH SPACE
Lockheed Martin-built Orion takes first steps on deep space journey

UTC Aerospace Systems provides critical control systems for Orion

Orion Flight 'Milestone' in Obama's Space Policy: White House

Orion test sets stage for ESA service module

TECH SPACE
Service module of China's returned lunar orbiter reaches L2 point

China Launches Second Disaster Relief Satellite

China expects to introduce space law around 2020

China launches new remote sensing satellite

TECH SPACE
OPALS: Light Beams Let Data Rates Soar

ISS Enables Interplanetary Space Exploration

NASA's CATS Eyes Clouds, Smoke and Dust from the Space Station

3-D Printer Creates First Object in Space on ISS

TECH SPACE
Soyuz Installed at Baikonur, Expected to Launch Wednesday

ADS to provide key elements for Vega launcher

Ariane 5 delivers DIRECTV-14 and GSAT-16 to orbit

Europe to build new-generation Ariane 6 rocket

TECH SPACE
Finding infant earths and potential life just got easier

Queen's scientist leads study of 'Super-Earth'

Finding infant earths and potential life just got easier

'Mirage Earth' exoplanets may have burned away chances for life

TECH SPACE
Geckos are sticky without effort

Solid-state proteins maximize the intensity of fluorescent-protein-based lasers

Marie Curie gets advice from Albert Einstein in lost letter

See it, touch it, feel it




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.