Photo credit: American Chemical Society
New compound helps distinguish blood (C) from coffee (A) or tea (B).
A new compound combining the antimalarial drug artemisinin and luminol could help crime scene technicians detect blood spots with fewer false identifications.
Luminol, which is often combined with hydrogen peroxide, reacts with the heme groups in blood, producing a bright blue glow, known as chemiluminescence.
However, luminol is subject to false positives due to interference from biomolecules and metal ions, and from the breakdown products of hydrogen peroxide.
Artemisinin is a natural peroxide that is more stable than hydrogen peroxide in the presence of common ions and more resistant to interference.
So investigators decided to combine artemisinin with luminol in an effort to minimize erroneous bloodstain identifications. They showed that the luminol-artemisinin combination is more selective than luminol-hydrogen peroxide.
They challenged the new combination with components of bleaches and disinfectants, which criminals often use to clean up a crime scene. The new compound could distinguish blood from coffee, tea, and brown sugar stains.
The investigators also successfully tested the new luminol-artemisinin compound using a smartphone to obtain results. This new method could provide highly accurate, cost-effective, on-scene analyses.
They believe the favorable sensitivity and selectivity of this method makes it promising in forensic pursuits.
Guobao Xu, PhD, of the Chinese Academy of Sciences in Beijing, People’s Republic of China, and colleagues reported these findings in the American Chemical Society’s journal, Analytical Chemistry.
The authors received funding from the National Natural Science Foundation of China, the National Key Research and Development Program of China, the Chinese Academy of Science President's International Fellowship Initiative Project, and the Chinese Academy of Sciences-the Academy of Sciences for the Developing World President's Fellowship Programme.
