Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Sniffer Dog on a Chip

Dog on a chip: Explosives can be detected with unprecedented sensitivity by using arrays of silicon nanowire field-effect transistors modified with an electron-rich aminosilane monolayer, which form complexes with the analytes (see picture). These “nanosniffers” can be used to sense the presence of TNT at concentrations as low as 1×10−6 ppt, which is superior to that of sniffer dogs or any other known explosive detection method.
Dog on a chip: Explosives can be detected with unprecedented sensitivity by using arrays of silicon nanowire field-effect transistors modified with an electron-rich aminosilane monolayer, which form complexes with the analytes (see picture). These “nanosniffers” can be used to sense the presence of TNT at concentrations as low as 1×10−6 ppt, which is superior to that of sniffer dogs or any other known explosive detection method.

Abstract:
Highly sensitive TNT detection with nanowires

Sniffer Dog on a Chip

Weinheim, Germany | Posted on September 15th, 2010

To thwart possible terrorist attacks and to detect contamination on sites of former military installations, researchers have been concentrating their efforts in recent years on methods for the detection and analysis of explosives. Fernando Patolsky and his team at the University of Tel Aviv have now developed a novel sensor chip that detects trinitrotoluene (TNT), as well as other explosive species, with high sensitivity and without a concentration step. As the Israeli researchers report in the journal Angewandte Chemie, their detector is superior to sniffer dogs and all other previous detection methods for this explosive.

The difficulty with the detection of explosives such as TNT is their extremely low volatility. Methods available for the analysis of air samples are expensive and time-consuming, and require large, bulky instruments, laborious sample preparation, and expert handling. "There is a need for an inexpensive, miniaturizable method that allows for quick, easy, and robust high-throughput analysis in the field," says Patolsky.

The scientists built their sensor using the principle of a nanoscale field-effect transistor. In contrast to a current-controlled classical transistor, a field-effect transistor is switched by means of an electric field. At the core of the device are nanowires made of the semiconductor silicon. These were coated with a molecular layer made from special silicon compounds that contains amino groups (NH2). TNT molecules bind to these amino groups in the form of charge-transfer complexes. The binding process involves the transfer of electrons from the electron-rich amino groups to the electron-poor TNT. This change in the charge distribution on the surface of the nanowires modulates the electric field and leads to an abrupt change in the conductivity of the nanowires, which is easily measured.

To improve the signal-to-noise ratio and thus increase the sensitivity, the scientists equipped their chip with an array of about 200 individual sensors. "We are thus able to analyze liquid and gaseous samples without prior concentration or other sample preparation at previously unattainable sensitivities," says Patolsky. "We were able to analyze concentrations down to 0.1 ppt (parts per trillion); that is, one molecule of TNT in 10 quadrillion other molecules." The sensor can be quickly regenerated by washing and is selective for TNT; other related molecules do not react the same way.

"We are now creating a chip based on large arrays of nanosensors chemically modified with a large number of chemical receptors, with different binding capabilities, in order to detect a whole spectrum of explosive species in parallel," says Patolsky.

Author: Fernando Patolsky, Tel Aviv University (Israel), www.tau.ac.il/chemistry/patolsky/

Title: Supersensitive Detection of Explosives by Silicon Nanowire Arrays

Angewandte Chemie International Edition 2010, 49, No. 38, 6830-6835, Permalink to the article: dx.doi.org/10.1002/anie.201000847

####

For more information, please click here

Contacts:

Copyright © Angewandte Chemie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Feynman Prize Winners Announced! April 26th, 2015

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

Possible Futures

Printing Silicon on Paper, with Lasers April 21st, 2015

A glass fiber that brings light to a standstill: By coupling photons to atoms, light in a glass fiber can be slowed down to the speed of an express train; for a short while it can even be brought to a complete stop April 9th, 2015

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Sensors

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

New class of 3D-printed aerogels improve energy storage April 22nd, 2015

‘Oxford Instruments Young Nanoscientist India Award 2015’ to Prof. Arindam Ghosh April 20th, 2015

Optical resonance-based biosensors designed for medical applications April 18th, 2015

Announcements

Feynman Prize Winners Announced! April 26th, 2015

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

Homeland Security

UCLA nanoscientists are first to model atomic structures of three bacterial nanomachines: Cryo electron microscope enables scientists to explore the frontiers of targeted antibiotics April 21st, 2015

Optics, nanotechnology combined to create low-cost sensor for gases April 3rd, 2015

The Universitat Politècnica de València is coordinating a European project to develop a device for the quick and early diagnosis of cancer March 7th, 2015

Detecting chemical weapons with a color-changing film January 28th, 2015

Military

Electron spin brings order to high entropy alloys April 23rd, 2015

Engineer improves rechargeable batteries with MoS2 nano 'sandwich' April 18th, 2015

Cobalt film a clean-fuel find: Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water April 15th, 2015

MIT sensor detects spoiled meat: Tiny device could be incorporated into 'smart packaging' to improve food safety April 15th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project