October 5, 2009 By Blake Harris
Photo: Dr. Steven Bell uses the new Raman spectroscopy laser technology.
According to a news release issued today, scientists at Queen's University Belfast are developing new sensors to detect traces from chemical weapons in a matter of seconds. The sensors will also detect traces of illegal drugs, opening the door to not only speedy investigation of a suspected terrorist attack, but also more effective day to day drug interdictions.
The research is being led by Dr. Steven Bell of the School of Chemistry and Chemical Engineering at Queen's University of Belfast in collaboration with colleagues from the School of Pharmacy at Queen's University and Forensic Science Northern Ireland (FSNI).
The devices use special gel pads to 'swipe' an individual or crime scene to gather a sample. This is then analyzed by a scanning instrument that can detect the presence of chemicals within seconds.
The scanning instrument uses Raman Spectroscopy which involves shining a laser beam onto the suspected sample and measuring the energy of light that scatters from it to determine what chemical compound is present. According to the researchers, it is so sophisticated it can measure particles of a miniscule scale making detection faster and more accurate.
Normally this type of spectroscopy is not sensitive enough to detect low concentrations of chemicals, so here the sample is mixed with nanoscale silver particles which amplify the signals of compounds allowing even the smallest trace to be detected.
"Although we are still in the middle of the project we have finished much of the preliminary work and are now at the exciting stage where we put the various strands together to produce the integrated sensor device," Dr. Bell explained in the published statement. "For the future, we hope to be able to capitalize on this research and expand the range of chemicals and drugs which these sensors are able to detect."
One development envisioned by the researchers is a 'breathalyzer' type instrument that could be of particular use for roadside drugs testing, much in the same way that today police take breathalyzer samples to detect alcohol.
At present, police are only able to use a Field Impairment Test to determine if a person is driving under the influence of drugs. The accuracy of this method has been questioned because of concerns that it is easy to cheat.
"There are numerous areas, from medical diagnostics to environmental monitoring, where the ability to use simple field tests to detect traces of important indicator compounds would be invaluable," Dr. Bell added.
Bell and his collaborators have been working since 1999 to develop new Raman and SERS methods for analysis of illicit drugs, paints, fibers, materials and other physical evidence. It has already led to routine use of Raman methods within FSNI (Forensic Science Northern Ireland) laboratories for drugs intelligence. It is hoped that the new project, being conducted with input from FSNI, will move this research out of the laboratory and into the field.