Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New sensor array detects single molecules for the first time

08.03.2010
Carbon nanotube sensor detects hydrogen peroxide emanating from a single living cell

MIT chemical engineers have built a sensor array that, for the first time, can detect single molecules of hydrogen peroxide emanating from a single living cell.

Hydrogen peroxide has long been known to damage cells and their DNA, but scientists have recently uncovered evidence that points to a more beneficial role: it appears to act as a signaling molecule in a critical cell pathway that stimulates growth, among other functions.

When that pathway goes awry, cells can become cancerous, so understanding hydrogen peroxide's role could lead to new targets for potential cancer drugs, says Michael Strano, leader of the research team. Strano and his colleagues describe their new sensor array, which is made of carbon nanotubes, in the March 7 online edition of Nature Nanotechnology.

Strano's team used the array to study the flux of hydrogen peroxide that occurs when a common growth factor called EGF activates its target, a receptor known as EGFR, located on cell surfaces. For the first time, the team showed that hydrogen peroxide levels more than double when EGFR is activated.

EGF and other growth factors induce cells to grow or divide through a complex cascade of reactions inside the cell. It's still unclear exactly how hydrogen peroxide affects this process, but Strano speculates that it may somehow amplify the EGFR signal, reinforcing the message to the cell. Because hydrogen peroxide is a small molecule that doesn't diffuse far (about 200 nanometers), the signal would be limited to the cell where it was produced.

The team also found that in skin cancer cells, believed to have overactive EGFR activity, the hydrogen peroxide flux was 10 times greater than in normal cells. Because of that dramatic difference, Strano believes this technology could be useful in building diagnostic devices for some types of cancer.

"You could envision a small handheld device, for example, which your doctor could point at some tissue in a minimally invasive manner and tell if this pathway is corrupted," he says.

Strano points out that this is the first time an array of sensors with single-molecule specificity has ever been demonstrated. He and his colleagues derived mathematically that such an array can distinguish "near field" molecular generation from that which takes place far from the sensor surface. "Arrays of this type have the ability to distinguish, for example, if single molecules are coming from an enzyme located on the cell surface, or from deep within the cell," says Strano.

How they did it: The sensor consists of a film of carbon nanotubes embedded in collagen. Cells can grow on the collagen surface, and the collagen also attracts and traps hydrogen peroxide released by the cell. When the nanotubes come in contact with the trapped hydrogen peroxide, their fluorescence flickers. By counting the flickers, one can obtain an accurate count of the incident molecules.

Next steps: Researchers in Strano's lab plan to study different forms of the EGF receptor to better characterize the hydrogen peroxide flux and its role in cell signaling. They have already discovered that molecules of oxygen are consumed to generate the peroxide.

Strano's team is also working on carbon nanotube sensors for other molecules. The team has already successfully tested sensors for nitric oxide and ATP (the molecule that carries energy within a cell). "The list of biomolecules that we can now detect very specifically and selectively is growing rapidly," says Strano, who also points out that the ability to detect and count single molecules sets carbon nanotubes apart from many other nanosensor platforms.

Source: "Detection of single-molecule H2O2 signaling from epidermal growth factor receptor using fluorescent single-walled carbon nanotubes," Hong Jin, Daniel Heller, Marie Kalbacova, Jong-Ho Kim, Jingqing Zhang, Ardemis Boghossian, Narendra Maheshri, Michael Strano. Nature Nanotechnology, March 7.

Jennifer Hirsch | EurekAlert!
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>