Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Temp-controlled 'nanopores' may allow detailed blood analysis

11.03.2013
Tiny biomolecular chambers called nanopores that can be selectively heated may help doctors diagnose disease more effectively if recent research by a team at the National Institute of Standards and Technology (NIST), Wheaton College, and Virginia Commonwealth University (VCU) proves effective. Though the findings* may be years away from application in the clinic, they may one day improve doctors' ability to search the bloodstream quickly for indicators of disease—a longstanding goal of medical research.

The team has pioneered work on the use of nanopores—tiny chambers that mimic the ion channels in the membranes of cells—for the detection and identification of a wide range of molecules, including DNA. Ion channels are the gateways by which the cell admits and expels materials like proteins, ions and nucleic acids. The typical ion channel is so small that only one molecule can fit inside at a time.


By tethering gold nanoparticles (large spheres in top image) to the nanopore (violet), the temperature around the nanopore can be changed quickly and precisely with laser light, allowing scientists to distinguish between similar molecules in the pore that behave differently under varied temperature conditions.

Credit: Robertson/NIST

Previously, team members inserted a nanopore into an artificial cell membrane, which they placed between two electrodes. With this setup, they could drive individual molecules into the nanopore and trap them there for a few milliseconds, enough to explore some of their physical characteristics.

"A single molecule creates a marked change in current that flows through the pore, which allows us to measure the molecule's mass and electrical charge with high accuracy," says Joseph Reiner, a physicist at VCU who previously worked at NIST. "This enables discrimination between different molecules at high resolution. But for real-world medical work, doctors and clinicians will need even more advanced measurement capability."

A goal of the team's work is to differentiate among not just several types of molecules, but among the many thousands of different proteins and other biomarkers in our bloodstream. For example, changes in protein levels can indicate the onset of disease, but with so many similar molecules in the mix, it is important not to mistake one for another. So the team expanded their measurement capability by attaching gold nanoparticles to engineered nanopores, "which provides another means to discriminate between various molecular species via temperature control," Reiner says.

The team attached gold nanoparticles to the nanopore via tethers made from complementary DNA strands. Gold's ability to absorb light and quickly convert its energy to heat that conducts into the adjacent solution allows the team to alter the temperature of the nanopore with a laser at will, dynamically changing the way individual molecules interact with it.

"Historically, sudden temperature changes were used to determine the rates of chemical reactions that were previously inaccessible to measurement," says NIST biophysicist John Kasianowicz. "The ability to rapidly change temperatures in volumes commensurate with the size of single molecules will permit the separation of subtly different species. This will not only aid the detection and identification of biomarkers, it will also help develop a deeper understanding of thermodynamic and kinetic processes in single molecules."

The team is researching ways to improve semiconductor-based nanopores, which could further expand this new measurement capability.

*J.E. Reiner, J.W.F. Robertson, D.L. Burden, L.K. Burden, A. Balijepalli and J.J. Kasianowicz. Temperature sculpting in yoctoliter volumes. Journal of the American Chemical Society, DOI: 10.1021/ja309892e. Jan. 24, 2013.

Chad Boutin | EurekAlert!
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg

nachricht The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>