Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Synthetic Scent Hounds

18.05.2012
Nanostructured sensor for the detection of very low concentrations of explosive

To prevent terrorist attacks at airports, it would be helpful to detect extremely low concentrations of explosives easily and reliably. Despite the development of various sensor technologies, dogs continue to be the most efficient detectors. In the journal Angewandte Chemie, a German and French team has now described a type of micromechanical sensor with a structure derived from the sense organs of butterflies.

One approach used for sensors is based on microcantilevers. These are tiny flexible cantilevers like those used to scan surfaces with atomic force microscopes. When used in “chemical noses” the microcantilivers are coated with a material that specifically binds to the analytes being detected. Cantilevers can vibrate like springs. When analyte molecules are bound to a microcantilever, its mass changes along with its frequency of vibration. This change can be measured.

Because of their very low vapor pressure at room temperature, the highly sensitive, reliable detection of explosives remains a big challenge. In order to make microcantilevers more sensitive to the explosive trinitrotoluene (TNT), research groups led by Denis Spitzer at the French-German Research Institute of Saint Louis and Valérie Keller at the Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse in Strasbourg have now taken inspiration from the highly sensitive sense organ of some types of butterfly. Male silk moths use this organ to recognize pheromone molecules excreted by females as they land on its broad antennae. These antennae are covered with sensilla, which are porous hairs containing chemonsensing neurons.

The scientists equipped their microcantilevers like the butterfly antennae. They coated them with a dense three-dimensionally ordered layer of titanium dioxide nanotubes oriented vertically, like the butterfly sensilla. This has several advantages: the specific surface of the microcantilevers is significantly increased; titanium dioxide binds well to substances that contain nitro groups, which are characteristic of TNT and other explosives; also, the tubes have an open structure, which improves the movement of mass and ensures a rapid sensor response.

The tubes are about 1700 nm long and have an outer diameter of about 100 nm and a wall thickness of 20 nm. Each cantilever holds about 500,000 of these nanotubes.

For test purposes, the researchers vaporized TNA by heating a tiny crystal. The sensor was able to detect concentrations of less than one part per trillion (ppt) within 3 minutes. The researchers are now working on building a selective detector system for explosives or other gases based on this method.

About the Author
Denis Spitzer is the Director of the NS3E Laboratory, which is a joined research Unit between the French-German Research Institute of Saint-Louis (ISL) and the french Centre National de la Recherche Scientifique (CNRS). He received his Ph.D. degree in physical chemistry from the University Louis Pasteur of Strasbourg in 1993. After some years dedicated to technology transfer, he went back to ISL in 2000.His main research specialties are the elaboration and the study of nanoenergetic materials, the detection of explosives and the imaging of organic compounds by atomic force microscopy. He is the author of 12 patents.
Author: Denis Spitzer, Institut Franco-Allemand de Recherches de Saint-Louis (France), mailto:denis.spitzer@isl.eu
Title: Bio-Inspired Nanostructured Sensor for the Detection of Ultralow Concentrations of Explosives

Angewandte Chemie International Edition 2012, 51, No. 22, 5334–5338, Permalink to the article: http://dx.doi.org/10.1002/anie.201108251

Denis Spitzer | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin 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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>