Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Dog-on-a-chip’ could replace drug-sniffing canines

30.10.2003


Police dogs across the country could soon be out of work, replaced by an electronic "dog-on-a-chip" that sniffs out cocaine and other narcotics. Scientists at Georgia Tech have created a new detection tool that is portable, inexpensive, and doesn’t require feeding or grooming. They say it is superior to previous "electronic noses" designed for this purpose.



The report will appear in the Nov. 15 edition of Analytical Chemistry, a peer-reviewed journal of the American Chemical Society, the world’s largest scientific society.

"Our technology provides a hand-held sensing device capable of real-time detection, reducing the time between drug seizure and laboratory analysis," says Desmond Stubbs, a doctoral candidate in chemistry working under the direction of William Hunt, Ph.D., a professor of electrical engineering at Georgia Tech in Atlanta.


The sensor, which performed well in the lab and in a field test with the Georgia Bureau of Investigation, is "an elegant fusion of biotechnology and microelectronics," according to Hunt. This combination of disciplines makes the sensor superior to previous "electronic noses." The U.S. government will spend more than $19 billion this year in the war on drugs, according to the Office of National Drug Policy. Police dogs are important tools in this battle; their highly developed olfactory systems can detect small molecules in the part-per-billion range.

But using dogs has its drawbacks. They require expensive handlers to train and care for them, and the seized drugs must still be sent to the lab for further analysis — adding trained technicians and costly lab equipment to the tab.

Plus, scientists still don’t know exactly what chemicals the dogs are sensing, allowing for significant variations from one dog to the next. Dogs also have trouble detecting specific drug targets in the presence of other odors, such as coffee grounds. "Unfortunately, the illicit drug traffickers are aware of this and invariably mask their product with different chemicals to evade authorities," Stubbs says.

The new device addresses all of these issues.

Two key features of any vapor-sensing tool are sensitivity and specificity. Sensitivity is the ability to detect very small amounts of a chemical. Specificity is the ability to differentiate a certain chemical from a group of many similar ones (e.g., cocaine from coffee grounds).

The dog-on-a-chip can sense cocaine at a few trillionths of a gram. This sensitivity is achieved through surface acoustic wave (SAW) electronics, a method of detecting a chemical by measuring the disturbance it causes in sound waves across a tiny quartz crystal. This is a fairly common analytical method, and it has been used in other electronic noses, but by itself it does not address the problem of specificity.

The new chip goes a step further by incorporating monoclonal antibodies — cloned copies of proteins called antibodies that the immune system produces to fight foreign invaders. The researchers used anti-benzoylecgonine (anti-BZE) in the device because it differs only slightly in structure from cocaine, allowing it to bind preferentially to that molecule.

The SAW sensor is coated with a thin layer of anti-BZE. When a vapor sample passes through, cocaine molecules attach to anti-BZE molecules, causing a disturbance in the sound waves on the quartz crystal that is detected as an electrical signal.

"We are the first group to use specific antibodies to differentiate similar sized molecules in a complex vapor sample," Hunt says. This gives the dog-on-a-chip an advantage over its canine competitors and other electronic devices. It will also be significantly cheaper and less time-consuming by removing many of the steps from the current detection protocol.

The new device was carefully calibrated in a laboratory setting, and then it was put to the test in the field. "In field tests conducted at the Georgia Bureau of Investigation, we were able to detect cocaine obtained during an actual drug seizure," Stubbs says. "By simply drawing the vapor through our prototype device, we got a positive detection in a matter of seconds."

The ability to detect and identify small, non-volatile molecules like cocaine based on their electronic vapor signature could also be used in airports and other locations to detect explosives and chemical warfare agents, according to the researchers.

The U.S. Customs Service and the Office of National Drug Control Policy (ONDCP) provided funding for this research.

Michael Bernstein | EurekAlert!
Further information:
http://www.acs.org/

More articles from Process Engineering:

nachricht Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>