A novel technique of detecting cocaine abuse through a simple fingerprint has been developed by researchers from multiple universities from UK and the Netherlands paving way for a secure, non-invasive and hygienic drug detection method.

The research, led by University of Surrey and published in the journal Analyst, demonstrates for the first time that cocaine abuse can be tested by non-invasive techniques by detecting excreted metabolites – benzoylecgonine and methylecgonine – resulting from abuse of drugs. These chemicals are found in fingerprint residue, which the researchers detected using analytical chemistry technique known as ambient mass spectrometry.

For their research, scientists sprayed a beam of solvent onto the fingerprint slide (a technique known as Desorption Electrospray Ionisation, or DESI) to determine if these metabolites were present. DESI has found use in a number of forensic applications, but has never been used to demonstrate drug use says lead author Dr Melanie Bailey from the University of Surrey.

Researchers took fingerprints and oral fluid from patients attending a drug and alcohol treatment service. Using a technique called gas chromatography mass spectrometry (GC-MS), they tested the oral fluid of patients for the presence of cocaine and benzoylecgonine. They then employed DESI, which operates under ambient conditions and Ion Mobility Tandem Mass Spectrometry Matrix Assisted Laser Desorption Ionization (MALDI-IMS-MS/MS) and Secondary Ion Mass Spectrometry (SIMS), to analyse the corresponding fingerprints.

The detection of cocaine, benzoylecgonine (BZE) and methylecgonine (EME) in latent fingerprints using both DESI and MALDI showed good correlation with oral fluid testing, the research paper notes.

“The mass spectrometry techniques used here offer a high level of selectivity and consume only a small area of a single fingerprint, allowing repeat and high throughput analyses of a single sample”, the researchers conclude.

“The beauty of this method is that, not only is it non-invasive and more hygienic than testing blood or saliva, it can’t be faked,” added Dr Bailey. “By the very nature of the test, the identity of the subject is captured within the fingerprint ridge detail itself.”

It is anticipated that this technology could see the introduction of portable drug tests for law enforcement agencies to use within the next decade.

“We are only bound by the size of the current technology. Companies are already working on miniaturised mass spectrometers, and in the future portable fingerprint drugs tests could be deployed. This will help to protect the public and indeed provide a much safer test for drug users,” said Dr Bailey.

Researchers from Netherlands Forensic Institute (NL), the National Physical Laboratory (UK), King’s College London (UK) and Sheffield Hallam University (UK) were a part of the research.