New Fingerprint Test Tells What a Person Has Touched ,Reveals Drug Use and Medical History: method raises privacy issues, and provides breakthrough in surgery
Fingerprints can reveal critical evidence, as well as an identity, with the use of a new technology developed at Purdue University that detects trace amounts of explosives, drugs or other materials left behind in the prints. It reads and provides an image of a fingerprint's chemical signature and can determine specific medical conditions.
Fingerprints can reveal critical evidence, as well as an identity, with the use of a new technology developed at Purdue University that detects trace amounts of explosives, drugs or other materials left behind in the prints. It reads and provides an image of a fingerprint's chemical signature and can determine specific medical conditions.
Writing in Friday’s issue of the journal Science . Graham Cooks, a professor of chemistry at Purdue University, describe how a laboratory technique, mass spectrometry, could find a wider application in crime investigations. "The classic example of a fingerprint is an ink imprint showing the unique swirls and loops used for identification, but fingerprints also leave behind a unique distribution of molecular compounds," Cooks said. "Some of the residues left behind are from naturally occurring compounds in the skin and some are from other surfaces or materials a person has touched."In Dr. Cooks’s method, a tiny spray of liquid that has been electrically charged, either water or water and alcohol, is sprayed on a tiny bit of the fingerprint. The droplets dissolve compounds in the fingerprints and splash them off the surface into the analyzer. The liquid is heated and evaporates, and the electrical charge is transferred to the fingerprint molecules, which are then identified by a device called a mass spectrometer. The process is repeated over the entire fingerprint, producing a two-dimensional image.The researchers call the technique desorption electrospray ionization, or Desi, for short.Because the spatial resolution is on the order of the width of a human hair, the Desi technique did not just detect the presence of, for instance, cocaine, but literally showed a pattern of cocaine in the shape of the fingerprint, leaving no doubt who had left the cocaine behind.
No comments:
Post a Comment