At crime scenes , forensic analysts work alongside investigators to collect evidence and analyze it for chemical, biological and physical markers, such as DNA.
Now, researchers at the Beersheba-based Ben-Gurion University of the Negev say they have found a way to do the job better with a device they developed made up of luminol — a chemical substance used by criminologists to detect blood and proteins — and nanosized particles of gold or silver, which amplify the emission of light when blood spots are detected.
Luminol reacts with microscopic bits of biological residue invisible to the naked eye, which then emit light, revealing their presence.
But luminol is not very good emitter of light, so the Ben-Gurion University researchers set out to find ways to enhance its ability to emit light.
Putting luminol in one syringe and gold and silver particles in another, they created a tube-like device that is fed by both syringes on its sides.
When forensic analysts suspect they may be blood at a certain location, they would place a sample on the edge of the tube. The mixture absorbs the light emitted from the luminol and then re-emits it, with a stronger light, that makes it easier to see, said Dr. Alina Karabchevsky of the Electro-Optics and Photonics Engineering Department, School of Electrical and Computer Engineering and Ilse Katz Institute for Nanoscale Science & Technology at BGU, who developed the technology.
The device invented by Karabchevsky and her team not only increases the chemiluminescence intensity several-fold but also prolongs the glow time of luminol, enabling the detection of much smaller blood samples at a forensic scene, the researchers said in a statement.
“Identifying trace quantities of blood can increase the efficiency and accuracy of a forensic investigation of a crime scene, but requires more sensitive detectors than those that are currently available,” said Netta Cohen, CEO of BGN Technologies, the technology transfer arm of the university. “The method developed by BGU researchers will enable development of future detectors with improved sensitivity. We are currently looking for partners for further developing this promising patented invention.”