Israeli researchers improve forensic test for blood trace detection

Israeli researchers have developed an improved forensic test for detecting blood traces, which could increase efficiency and accuracy in criminal investigations, said a report by the Southern Ben Gurion University.

Identifying blood traces requires more sensitive sensors than those available at present, and the new method will enable the development of future sensors with improved sensitivity, the report said on Monday.

Criminologists use luminol – a chemical that emits increased light in the presence of blood – to detect microscopic blood droplets, as well as low concentrations of hydrogen peroxide, proteins and DNA, all hidden from the human eye.

The new method combines the use of luminol with nanometre spheres of gold or silver, placed in a specially designed curved device that allows the flow of minimal quantities of liquids.

The spheres are used by nanometre-scale antennas that increase luminol’s light emission and simplify the detection of blood traces due to the integration with the chip.

The use of luminol-based chemical emission to identify these biological residues is preferable because it does not rely on external light sources and is not expensive.

The new chip not only increases luminol’s light emissions but also extends the duration of the emission and allows the identification of much smaller blood samples at crime scenes.

According to the researchers, the findings pave the way for producing integrated chips that are based on minimum quantities of liquids to be tested.

They added that the implementation of this phenomenon will lead to improved light-emitting sensors not only for the use of crime science but also for biological and chemical research and optoelectronic lasers, Xinhua reports.