Navigation Links
All wrapped up: K-State researcher's graphene cloak protects bacteria, leading to better images

MANHATTAN, KAN. -- It's a cloak that surpasses all others: a microscopic carbon cloak made of graphene that could change the way bacteria and other cells are imaged.

Vikas Berry, assistant professor of chemical engineering at Kansas State University, and his research team are wrapping bacteria with graphene to address current challenges with imaging bacteria under electron microscopes. Berry's method creates a carbon cloak that protects the bacteria, allowing them to be imaged at their natural size and increasing the image's resolution.

Graphene is a form of carbon that is only one atom thick, giving it several important properties: it's impermeable, it's the strongest nanomaterial, it's optically transparent and it has high thermal conductance.

"Graphene is the next-generation material," Berry said. "Although only an atom thick, graphene does not allow even the smallest of molecules to pass through. Furthermore, it's strong and highly flexible so it can conform to any shape."

Berry's team has been researching graphene for three years, and Berry recently saw a connection between graphene and cell imaging research. Because graphene is impermeable, he decided to use the material to preserve the size of bacterial cells imaged under high-vacuum electron microscopes.

The research results appear in the paper "Impermeable Graphenic Encasement of Bacteria," which was published in a recent issue of Nano Letters, a monthly scientific journal published by the American Chemical Society. The team's preliminary research appeared in Nature News in 2010.

The current challenge with cell imaging occurs when scientists use electron microscopes to image bacterial cells. Because these microscopes require a high vacuum, they remove water from the cells. Biological cells contain 70 to 80 percent water, and the result is a severely shrunk cell. As a result, it is challenging to obtain an accurate image of the cells and their components in their natural state.

But Berry and his team created a solution to the imaging challenge by applying graphene. The graphene acts as an impermeable cloak around the bacteria so that the cells retain water and don't shrink under the high vacuum of electron microscopes. This provides a microscopic image of the cell at its natural size.

The carbon cloaks can be wrapped around the bacteria using two methods. The first method involves putting a sheet of graphene on top of the bacteria, much like covering up with a bed sheet. The other method involves wrapping the bacteria with a graphene solution, where the graphene sheets swaddle the bacteria. In both cases the graphene sheets were functionalized with a protein to enhance binding with the bacterial cell wall.

Under the high vacuum of an electron microscope, the wrapped bacteria did not change in size for 30 minutes, giving scientists enough time to observe them. This is a direct result of the high strength and impermeability of the graphene cloak, Berry said.

Graphene's other extraordinary properties enhance the imaging resolution in microscopy. Its electron-transparency enables a clean imaging of the cells. Since graphene is a good conductor of heat and electricity, the local electronic-charging and heating is conducted off the graphene cloak, giving a clear view of the bacterial cell well. Unwrapped bacterial cells appear dark with an indistinguishable cell wall.

"Uniquely, graphene has all the properties needed to image bacteria at high resolutions," Berry said. "The project provides a very simple route to image samples in their native wet state."

The process has potential to influence future research. Scientists have always had trouble observing liquid samples under electron microscopes, but using carbon cloaks could allow them to image wet samples in a vacuum. Graphene's strong and impermeable characteristics ensure that wrapped cells can be easily imaged without degrading them. Berry said it might be possible in the future to use graphene to keep bacterium alive in a vacuum while observing its biochemistry under a microscope.

The research also paves the way for enhanced protein microscopy. Proteins act differently when they are dry and when they are in an aqueous solution. So far most protein studies have been conducted in dry phases, but Berry's research may allow proteins to be observed more in aqueous environments.

"This research could be the point of evolution for processing of sensitive samples with graphene to achieve enhanced imaging," Berry said.


Contact: Vikas Berry
Kansas State University

Related biology news :

1. K-State research: Freshwater pollution costs US at least $4.3 billion a year
2. Researchers to use K-States BSL-3 Lab for $1 million study of fungus threatening wheat crops
3. K-State biologist collaborating with researchers in Africa on grassland sustainability, biodiversity
4. K-State researchers help Epitopix license the United States first E. coli O157 vaccine for cattle
5. K-State researchers work with university in Ghana to create biofuels from native tree seeds
6. K-State using Second Life island to help high school students learn earth science
7. K-State researcher finds 1918 flu resulted in current lineage of H1N1 swine influenza viruses
8. K-State host to workshop on rapid methods to detect microorganisms in food
9. Researchers from around the globe coming to K-State June 21 for workshop on Fusarium fungus
10. K-State plant pathologists develop online teaching modules used globally
11. K-State researcher, collaborators study virulence of pandemic H1N1 virus
Post Your Comments:
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
(Date:3/29/2016)... 2016 LegacyXChange, Inc. (OTC: ... SelectaDNA/CSI Protect are pleased to announce our successful effort ... variety of writing instruments, ensuring athletes signatures against counterfeiting ... from athletes on LegacyXChange will be assured of ongoing ... Bill Bollander , CEO states, "By ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Calif. , June 23, 2016  The Prostate Cancer Foundation ... increasingly precise treatments and faster cures for prostate cancer. Members of the Class ... across 15 countries. Read More About the Class of ... ... ...
(Date:6/23/2016)... ... , ... Supplyframe, the Industry Network for electronics hardware design ... Located in Pasadena, Calif., the Design Lab’s mission is to bring together inventors ... and brought to market. , The Design Lab is Supplyframe’s physical representation of ...
(Date:6/23/2016)... , June 23, 2016 Apellis ... Phase 1 clinical trials of its complement C3 ... single and multiple ascending dose studies designed to ... (PD) of subcutaneous injection in healthy adult volunteers. ... (SC) either as a single dose (ranging from ...
(Date:6/23/2016)... YORK , June 23, 2016 ... trading session at 4,833.32, down 0.22%; the Dow Jones Industrial ... S&P 500 closed at 2,085.45, down 0.17%. has initiated ... INFI ), Nektar Therapeutics (NASDAQ: NKTR ), ... Therapeutics Inc. (NASDAQ: BIND ). Learn more about ...
Breaking Biology Technology: