( Using lasers and tuning forks research...)New sensor detects gaseous chemical weapon surrogates in 45 seconds

Using lasers and tuning forks, researchers at Pacific Northwest National Laboratory have developed a chemical weapon agent sensing technique that promises to meet or exceed current and emerging defense and homeland security chemical detection requirements. The technique, called Quartz Laser Photo-Acoustic Sensing, or "QPAS," is now ready for prototyping and field testing.

PNNL, a Department of Energy national laboratory, has demonstrated QPAS's ability to detect gaseous nerve agent surrogates. In one test, researchers used diisopropyl methyl phosphonate (DIMP), which is a chemical compound that's similar to sarin. QPAS detected DIMP at the sub-part-per-billion level in less than one minute. The miniscule level is similar to letting one drop of liquid DIMP evaporate into a volume of air that would fill more than two Olympic-size swimming pools.

"QPAS is an extremely sensitive and selective chemical detection technique that can be miniaturized and yet is still practical to operate in field environments," said Michael Wojcik, a research scientist at PNNL. "The laser, tuning fork and other technology needed for QPAS are so simple, and yet robust, that further development is a low-risk investment, and we're eager to take it to the next level."

The instrument is based on Laser Photo-Acoustic Sensing, or LPAS, and infrared Quantum Cascade Lasers, or QCLs. LPAS is an exquisitely sensitive form of optical absorption spectroscopy, where a pulsed laser beam creates a brief absorption in a sample gas, which in turn creates a very small acoustic signal. A miniature quartz tuning fork acts as a "microphone" to record the resulting sound wave.

PNNL researchers paired multiple QCLs with the tuning forks, allowing simultaneous examination of a single sample at many infrared wavelengths. Nearly every molecule has unique optical properties at infrared wavelengths between three and 12 micrometers, and QCLs provide access to any wavelength in this
'"/>

Source:DOE/Pacific Northwest National Laboratory

Page: 1 2
Related biology news :

1. Study shows nanoshells ideal as chemical nanosensors
2. Polymers with copper show promise for implanted sensors
3. Bad aftertaste? New sensory on/off switch may cure bane of artificial sweetener search
4. Aptamer-based Biosensor screens Air Force personnel and equipment
5. Grasshopper love songs give insight into sensory tuning
6. Have a taste for fat? Yes! A sensor in the mouth promotes preference for fatty foods
7. New nanosensor uses quantum dots to detect DNA
8. Portable cocaine sensor developed at UC Santa Barbara
9. A biosensor layered like lasagna
10. Rochester scientists develop fast-working biosensor
11. Chemical signaling helps regulate sensory map formation in the brain