Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice develops nanosensor for precision chemical analysis

10.01.2003


Nanoshell sensor opens door for new methods to exam single molecules



Nanotechnology researchers at Rice University have demonstrated the ability to precisely control the electromagnetic field around nanoparticles, opening the door for chemical screening techniques that could allow doctors, life scientists and chemists to routinely analyze samples as small as a single molecule.

The research is detailed in the current issue of Applied Physics Letters. It builds upon a widely used method of molecular analysis called Raman spectroscopy and capitalizes on the tunable optical properties of metal nanoshells, a novel type of nanoparticle invented at Rice.


"This result is extremely important because it is the first time that anyone has actually designed and engineered a nanosensor specifically for obtaining chemical information," said nanoshell inventor Naomi Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering. "There are widespread applications for this technology in environmental science, chemistry and biosensing, and it may have very important applications in the early detection of cancer."

Scientists commonly use spectroscopy to discern detailed information about everything from distant galaxies to individual molecules. By studying the spectrum of light that an object emits, scientists can decipher which elements are present in the sample, and in some cases, how those elements relate to one another. Raman spectroscopy, in particular, allows scientists to observe the vibrational states of molecules, giving clues about where and how much molecules bend, for example, and serves as a "fingerprint" for the identification of specific molecules that may be of interest, such as environmental contaminants or chemical or biological toxins.

Scientists have long known that they could boost the Raman light emissions from a sample by a million times or more by placing the sample next to small particles of metal called colloids. Scientists have even observed single molecules with this method, but they have never been able to precisely control the electromagnetic state of the metal colloids, so results and interpretations of such studies vary widely.

Rice’s research offers scientists a chance to precisely control "surface enhanced Raman scattering," or SERS. In the Rice experiments, Halas’s group was able to dramatically enhance the SERS effect, making it up to a billion times more powerful in some cases.

Similar in structure to a hard-shelled chocolate candy, nanoshells are layered colloids that consist of a core of non-conducting material covered by a thin metallic shell. By varying the thickness of the conducting shell, researchers in Halas’ group can precisely tune the electric and optical properties of nanoshells.

Nanoshells are so useful for enhancing SERS and for other applications because of their size and precise structure. Nanoshells are just slightly larger than the size of molecules, measuring just a few tens of nanometers, or billionths of a meter, in diameter. Tuning the properties of nanoshells gives Halas’ group the ability to exert new forms of precision control at the molecular level.

The SERS research is described in the Jan. 13 issue of Applied Physics Letters in a paper titled "Controlling the Surface Enhanced Raman Effect via the Nanoshell Geometry," by J.B. Jackson, S.L. Westcott, L.R. Hirsch, J.L. West and N.J. Halas. The paper is available online at http://ojps.aip.org/aplo/.

The research was funded by the National Science Foundation, the Robert A. Welch Foundation and the Army Research Office’s Multidisciplinary University Research Initiative.

Jade Boyd | EurekAlert!
Further information:
http://chico.rice.edu/
http://ojps.aip.org/aplo/.

More articles from Process Engineering:

nachricht NRL develops laser processing method to increase efficiency of optoelectronic devices
16.04.2019 | Naval Research Laboratory

nachricht Hollow structures in 3D
29.03.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

New automated biological-sample analysis systems to accelerate disease detection

18.04.2019 | Life Sciences

Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

18.04.2019 | Physics and Astronomy

New eDNA technology used to quickly assess coral reefs

18.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>