Get fingerprints sharp even when the sign that saved from 2 months ago

According to Analytical Chemistry, a group of Chinese scientists have proposed new technology to use nanoparticles for a long time.

The researchers say that this method provides a more accurate fingerprint image than the standard methods used in forensic medicine.

In general, when collecting fingerprints at crime scenes, forensic experts use a carbon based powder, organic dyes or fluorescers to detect fingerprints. and palms. The choice of reactants depends on the nature and color of the substrate.

The new method provides a more accurate fingerprint image than the standard methods used in forensic medicine (Photo: Analytical Chemistry).

To increase the contrast of the fingerprints, Chinese researchers use these when they are exposed. But some surfaces, including metal and plastic, emit fluorescent light when exposed to ultraviolet light, and this can hide details of fingerprints.

Researcher Quan Yuan of Wuhan University and colleagues decided to eliminate the deviation. Because the surface of the material is no longer fluorescent after ultraviolet light is turned off, they look for a lighter material that will even glow after stopping ultraviolet irradiation.

They synthesized nanoparticles based on zinc and germanium compounds (Zn ₂ GeO ₄ ), containing 1.0% gallium and 0.5% manganese. The surface of the nanoparticles has been specially modified to better bond with the amino acids stored in the fingerprints.

During the experiment, the authors of the present invention pipetted the aqueous solution with the nanoparticles onto the surface where the fingerprints were stored. After half an hour they remove the liquid and the surface area is washed with phosphate buffer.

After ultraviolet radiation is directed directly onto the surface, it begins to fluoresce and obscure the glow of the fingerprint. But as soon as the UV light source is turned off, only light green fingerprints are visible, making it possible for everyone to see clearly all the fingerprints.

In addition, the new method can identify fingerprints from 60 days ago, a task too difficult to use traditional fingerprint identification methods.