Gel sensors to detect bomb chemicals and illegal drugs in seconds

Sensors that quickly detect chemicals used to make bombs are being developed by scientists at Queen’s University, Belfast. The devices will use special gel pads to "swipe" a person or crime scene to gather a sample which is then analyzed by a scanning instrument that can detect the presence of chemicals within seconds, much quicker than current analysis methods. This will allow better, faster decisions to be made in response to terrorist threats. The team is also working on devices that detect illegal drugs and will hopefully be deployed by police as roadside drug "breathalyzers".

Using 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, the scanning instrument is so sophisticated it can measure particles of a minuscule scale, making detection faster and more accurate.

To increase the sensitivity of the equipment, which is not normally keen enough to detect low concentrations of chemicals, the sample is mixed with nanoscale silver particles that amplify the signals of the 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,” said research leader Dr Steven Bell from Queen’s University.

“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.”

The team is hoping that its new sensors will prove useful also as "breathalyzers" in roadside drugs testing, in much the same way as the police take breathalyzer samples to detect alcohol. At present, local police officers have to rely on Field Impairment Tests to determine if a person is driving under the influence of drugs, which is thought to be subject to cheating and, hence, inaccurate.

Senior staff members from Forensic Science Northern Ireland (FSNI) will give significant input and feedback into the operation of the technology and to how it might be used in the wider community.

“We consider the work being carried out by researchers at Queen’s University extremely important and potentially very useful in driving forward the effectiveness, efficiency and speed of forensic science practice,” said Chief Executive of FSNI, Stan Brown.