Navigation Links
Graphene 'sandwich' improves images of biomolecules
Date:2/5/2014

By sandwiching a biological molecule between sheets of graphene, researchers at the University of Illinois at Chicago have obtained atomic-level images of the molecule in its natural watery environment.

The results are published online in advance of print in the journal Advanced Materials.

The molecule, ferritin, is a highly conserved protein that regulates the levels of iron in animals and plants. Ferritin can sequester excess iron, which can be toxic, and release it when it is needed.

"We found a way to encapsulate a liquid sample in two very thin layers of graphene sheets of carbon that are only one atom thick," said Canhui Wang, UIC graduate student in physics and first author of the study.

Electron microscopes let researchers see at the level of individual atoms. But to do so they must put the samples in a vacuum, making it impossible to image biomolecules in water in their natural, functional state. Biological samples have usually been placed in a container called a "liquid stage," wedged between relatively thick windows of silicon nitrate.

Robert Klie, the senior investigator on the study, says the thin layers of graphene in the new system work better, being nearly transparent.

"It's like the difference between looking through Saran Wrap and thick crystal," said Klie, who is associate professor of physics and mechanical and industrial engineering at UIC.

Not only resolution improved compared to the liquid stage. The graphene sandwich also minimizes damage to the sample from radiation, said Wang.

According to Wang, some people have calculated that just to barely visualize a sample requires the equivalent of 10 times the radiation 30 meters away from a 10 megaton hydrogen bomb. "We often use an electron beam that is several orders of magnitude more intense in our experiments," he said.

Graphene has an extraordinarily high thermal and electro-conductivity, said Klee, and is able to conduct away both the heat and the electrons generated as the electron microscope's beam passes through the sample.

Instead of using a low-energy beam to minimize damage, which yields a fuzzy picture that must be refined using a mathematical algorithm, the scientists were able to use high energies to generate images of ferritin at atomic level resolution. This enabled them to see, in a single functioning molecule, that iron oxide in ferritin's core changes its electrical charge, initiating the release of iron.

This insight into how the ferritin core handles iron may lead to a better understanding of what goes wrong in many human disorders, said Tolou Shokuhfar, assistant professor of mechanical engineering-engineering mechanics at Michigan Technological University and adjunct professor of physics at UIC, the principal investigator of the study.

"Defects in ferritin are associated with many diseases and disorders, but it has not been well understood how a dysfunctional ferritin works towards triggering life-threatening diseases in the brain and other parts of the human body," said Shokuhfar.

Wang had to solve a number of technical issues to develop the new technique, said Klie, but the graphene sandwich will now "open up analysis of biological and other difficult to image samples to almost anyone with an electron microscope." In contrast, he said, the standard liquid stage requires a large upfront investment in equipment and expensive preparation of each sample.

With graphene, once the technique is mastered, preparation of samples can be done quickly and cheaply, said Wang.


'/>"/>

Contact: Jeanne Galatzer-Levy
jgala@uic.edu
312-996-1583
University of Illinois at Chicago
Source:Eurekalert

Related biology news :

1. High-resolution atomic imaging of specimens in liquid by TEM using graphene liquid cell
2. Using graphene, scientists develop a less toxic way to rust-proof steel
3. Graphene plasmonics beats the drug cheats
4. Researchers use graphene quantum dots to detect humidity and pressure
5. Graphene nanoribbons for reading DNA
6. Graphene nanoribbons an ice-melting coat for radar
7. UNIST research team opens graphene band-gap
8. Satellite sandwich technique improves analysis of geographical data
9. Strip-till improves soybean yield
10. ORNL process improves catalytic rate of enzymes by 3,000 percent
11. Researchers discover potential explanation for why a diet high in DHA improves memory
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... First quarter 2016:   , ... the first quarter of 2015 The gross margin was ... 18.8) and the operating margin was 40% (-13) Earnings ... flow from operations was SEK 249.9 M (21.2) , ... SEK 7,000-8,500 M. The operating margin for 2016 is ...
(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:4/14/2016)... BioCatch ™, the global ... the appointment of Eyal Goldwerger as CEO. ... Goldwerger,s leadership appointment comes at a time of significant ... of its platform at several of the world,s largest ... unique cognitive and physiological factors, is a winner of ...
Breaking Biology News(10 mins):
(Date:6/22/2016)... ... June 22, 2016 , ... Quantitative ... business incubator and current participant in the Phase 1 Ventures program, is leveraging ... , Quantitative Radiology Solutions helps physicians make better treatment decisions by quantifying ...
(Date:6/22/2016)... (PRWEB) , ... June 21, 2016 , ... New light-based ... cutting into the tissue — promise to enable both compact, wearable devices for point-of-care ... even deeper under the skin. , Recent work and visionary future directions are detailed ...
(Date:6/22/2016)... SAN DIEGO , June 22, 2016 /PRNewswire/ ... that has developed a testing platform designed specifically ... the formation of their scientific advisory board (SAB). ... of directors, the SAB is chartered to advise ... infectious disease assay platform. Led by Dr. ...
(Date:6/22/2016)... June 22, 2016 On Tuesday, June ... 4,843.76, up 0.14%; the Dow Jones Industrial Average advanced 0.14% ... 2,088.90, up 0.27%. The gains were broad based as five ... has initiated coverage on the following equities: Minerva Neurosciences Inc. ... PTLA ), Trevena Inc. (NASDAQ: TRVN ), ...
Breaking Biology Technology: