Detonation of explosives and drugs from ... fingerprints

US scientists say police can detect traces of heroin, cocaine, marijuana and even explosives on a fingerprint.

A team of researchers at Purdue University in West Lafayette, Indiana, uses a technique called DESI (desorption electrospray ionization), whereby a chemical compound is sprayed onto the surface of the fingerprint. Analysis of droplets of solution is scattered on the stripe by spectroscopic method.

According to Prof. Graham Cooks, lead researcher, this technique provides a "chemical image" of fingerprints at higher resolutions than other techniques, and is capable of analyzing material quantities. has a mass of about one billionth of a gram.

A: The image of a fingerprint has a cocaine left on the glass. B: Image (A) after analysis by DESI technique on computer screen. Cocaine is represented by red dots. C: A finger inked and then pressed on paper. D: Image of finger (C) on computer screen using DESI technique. Photo: Dailymail.co.uk.

"The molecular compounds on a fingerprint can tell us which substances the subject has just touched," Graham said.

In this way, researchers can detect all the most sophisticated traces of compounds - represented by dots on print - on the fingerprint. It can detect a billionth of grams of narcotics and compounds from explosives. The DESI technique is also useful in identifying the metabolites and many other compounds from the sweat that fingerprints produce. The existence of such compounds can help scientists know the processes that are happening inside the body.

The team is also working on whether DESI can replace athletes' blood and urine tests.