Featured Research

from universities, journals, and other organizations

Gold nanoparticles quickly detect hazardous chemicals

Date:
November 20, 2012
Source:
Imperial College London
Summary:
Scientists have developed a system to quickly detect trace amounts of chemicals like pollutants, explosives or illegal drugs. The new system can pick out a single target molecule from 10,000 trillion water molecules within milliseconds, by trapping it on a self-assembling single layer of gold nanoparticles. The technology opens the way to develop devices that are compact, reusable and easy to assemble, and could have a range of uses including detecting illegal drugs, explosives, pollutants in rivers or nerve gases released into the air.

Gold nanoparticles align in a single layer in this graphical representation
Credit: Image courtesy of Imperial College London

Scientists at Imperial College London have developed a system to quickly detect trace amounts of chemicals like pollutants, explosives or illegal drugs.

The new system can pick out a single target molecule from 10,000 trillion water molecules within milliseconds, by trapping it on a self-assembling single layer of gold nanoparticles.

The team of scientists, all from the Department of Chemistry at Imperial, say this technology opens the way to develop devices that are compact, reusable and easy to assemble, and could have a range of uses including detecting illegal drugs, explosives, pollutants in rivers or nerve gases released into the air. Results of the research are published this week in Nature Materials.

In one potential use, such a device could detect tiny traces of explosives or other illegal substances left behind by criminals on the surfaces they touch. The advances made by this team would help law enforcers to identify and deal with such activities involving illegal substances.

Research co-author, Michael Cecchini, said: "Our system could solve a key problem of reliable and portable chemical testing for use in the outside world. It is very sensitive and could well be used to look for very small amounts of a specific molecule even in busy, public areas."

The target molecules are identified by an effect called Surface Enhanced Raman Scattering (SERS) of light. This technique, which has been around since the late 1970's, works because each molecule scatters light in a unique way. Previous research has shown that the signal can be amplified by catching molecules in a particular way on a layer of metal nanoparticles. However, these sheets are complex to manufacture.

The scientists overcame this problem by dealing with interfaces of two liquids that do not mix, such as water and oil, or water and air interface. By manipulating the electrical charge of the gold nanoparticles and the composition of the solution, they were able to create a situation where the particles line themselves up at the interface between the two non-mixable liquids, or between a liquid and the air.

"The trick to achieving this system's sensitivity to the target molecules was in finding the conditions at which nanoparticles would settle at the interface at close distances to each other without fusing together," commented another co-author Jack Paget.

If the nanoparticles are disturbed, they spontaneously arrange themselves back in the correct way make the device more robust than those made rigidly arranged particles. Research co-author, Vladimir Turek, said: "The system shows real promise for detectors for use in rough outdoor environmental and defence applications, since the liquids and nanoparticles can be easily replaced to regenerate the device."

This research is supported by funds from the UK's Defence Science and Technology Laboratory (DSTL) and the European Research Council (ERC) starting investigator grant. The cross-disciplinary team in the Department of Chemistry at Imperial is led by Dr Joshua Edel, an expert in applied nanoscience, and Professor Alexei Kornyshev, professor of chemical physics and expert in condensed matter. They are corresponding authors of the study, alongside research postgraduates Michael Cecchini, Vladimir Turek and Jack Paget.


Story Source:

The above story is based on materials provided by Imperial College London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael P. Cecchini, Vladimir A. Turek, Jack Paget, Alexei A. Kornyshev, Joshua B. Edel. Self-assembled nanoparticle arrays for multiphase trace analyte detection. Nature Materials, 2012; DOI: 10.1038/nmat3488

Cite This Page:

Imperial College London. "Gold nanoparticles quickly detect hazardous chemicals." ScienceDaily. ScienceDaily, 20 November 2012. <www.sciencedaily.com/releases/2012/11/121120152338.htm>.
Imperial College London. (2012, November 20). Gold nanoparticles quickly detect hazardous chemicals. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/11/121120152338.htm
Imperial College London. "Gold nanoparticles quickly detect hazardous chemicals." ScienceDaily. www.sciencedaily.com/releases/2012/11/121120152338.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins