Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Harnessing microbes, one by one, to build a better nanoworld

18.03.2005


Taking a new approach to the painstaking assembly of nanometer-sized machines, a team of scientists at the University of Wisconsin-Madison has successfully used single bacterial cells to make tiny bio-electronic circuits.

The work is important because it has the potential to make building the atomic-scale machines of the nanotechnologist far easier. It also may be the basis for a new class of biological sensors capable of near-instantaneous detection of dangerous biological agents such as anthrax.

The approach, reported here today (March 17, 2005) at a meeting of the American Chemical Society, suggests that microbes can serve as forms for complicated nanoscale structures, perhaps obviating, in part, the need for the tedious and time-consuming construction of devices at the smallest scale.



The work is also scheduled to appear in the April issue of the journal Nano Letters.

"One of the great challenges of nanotechnology remains the assembly of nanoscale objects into more complex systems," says Robert Hamers, a UW-Madison professor of chemistry and the senior author of the new reports. "We think that bacteria and other small biological systems can be used as templates for fabricating even more complex systems."

Toward that end, Hamers and his UW-Madison colleagues Joseph Beck, Lu Shang and Matthew Marcus, have developed a system in which living microbes, notably bacteria, are guided, one at a time, down a channel to a pair of electrodes barely a germ’s length apart. Slipping between the electrodes, the microbes, in effect, become electrical "junctions," giving researchers the ability to capture, interrogate and release bacterial cells one by one. Built into a sensor, such a capability would enable real-time detection of dangerous biological agents, including anthrax and other microbial pathogens. "The results here are significant because while there has been much attention paid to the ability to manipulate nanoscale objects such as nanotubes and nanowires across electrical contacts, for many applications the use of bacterial cells affords a number of potential advantages," Hamers says.

For example, capitalizing on the complex topography of the bacterial cell surface and microbial interactions with antibodies, scientists could potentially construct much more complex nanoscale structures through the natural ability of cells to dock with different kinds of molecules. Such a potential, Hamers argues, would be superior to the painstaking manipulation of individual nanosized components, such as the microscopic wires and tubes that comprise the raw materials of nanotechnology. "We spend a lot of time making tiny little nanowires and things of that sort, and then we try to direct them in place, but it is very hard," says Hamers. "However, bacteria and other biological systems can be thought of as nature’s nanowires that can be easily grown and manipulated."

In the series of experiments underpinning the new Wisconsin work, the group showed that it is possible to capture cells along an electrode and then direct them down a narrow channel that acts as a conveyor. Small gaps in the electrical contacts along the conveyor serve as traps that can hold single bacterial cells while their electrical properties are measured. Once the microbial interrogation is completed, the live cell can be released. "You can measure and release them at your leisure," explains Beck, the lead author of the Nano Letters paper and a UW-Madison postdoctoral fellow.

He says the chemicals naturally expressed on the surface of the bacterium could be wired in a way that would be the basis for a real-time biological sensor, a device that could be seeded in airports, stadiums, railway stations, skyscrapers, mailrooms and other public areas to sniff for dangerous biological agents that might be used in a bioterror event.

The device could be constructed, according to Beck, utilizing the natural features bacteria and other microbes use to sense their environments. The wired bacterial cells, coupled with modern microelectronics, would have the ability not only to detect dangerous agents (anthrax spores, for example) but they then could sound the alarm and call for help. "You could even engineer bacteria to have different surface molecules that you could capitalize on," says Beck.

For instance, it may be possible, the Wisconsin scientists say, to attach microscopic gold particles to the shell of the bacterium, making it more like a nanoscale gold wire.

Hamers believes the new work could be the basis for bringing nanotechnology and biology together in unprecedented ways.

Moreover, the ability to routinely and easily capture and analyze individual microbes will have implications for conventional biotechnology as well. For example, chemical modifications to the electrode traps might make it easier for scientists to retrieve specified cells from a complex mixture.

The work by Hamers’ group was funded by the National Science Foundation. The Wisconsin Alumni Research Foundation, a private, nonprofit organization that manages UW-Madison intellectual property, has applied for patents for the technology.

The paper on this research, ANYL 424, will be presented at 2:45 p.m., Thursday, March 17, at the San Diego Convention Center, Room 27A, during a symposium titled "Bioanalytical Techniques for Detection of Bacteria, Toxins and Proteins.

Robert J. Hamers | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences

nachricht The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>