Chemical In Henna Useful In New Fingerprinting Techniques

Henna, used to draw attractive designs on palms and in hair dyes, may become the latest tool in the fight against crime.

Curtin University of Technology researchers are developing new fingerprinting technologies using lawsone, a naturally occurring substance found in henna.



Simon Lewis, Associate Professor of Forensic Chemistry, said the new methods being tested had the potential to be an important complementary method to those currently used in fingerprint detection.

According to Curtin PhD student Renee Jelly, lawsone’s properties made it a very useful tool for law enforcement.

“Lawsone is the compound that gives henna its characteristic property for dying hair and skin a reddish brown colour,” she said.

“We have discovered that it reacts with the amino acids in invisible fingerprints on paper, which turn a purple-brown colour when treated with lawsone.

“These coloured fingerprints are also luminescent under a forensic light source.”

Miss Jelly’s thesis, Natural Products as Novel Reagents for the Development of Latent Fingermarks on Porous Surfaces, involves investigating a number of alternative materials to use in hunting for fingerprints on paper.

“Paper-based evidence, such as documents, wrapping material and containers, are frequently encountered in criminal investigations,” she said.

“The most widely used methods for detecting invisible fingerprints on these surfaces rely upon the detection of the amino acids present in natural skin secretions.

“Fingerprints formed in this way can be extremely long lived, with impressions in excess of 20 years of age being developed with amino acid sensitive treatments.

Source: medindia.net