Might the days of taking saliva or blood samples for drug tests be numbered? Scientists have figured out a way to use fingerprints instead, they report at Phys.org. Specifically, the researchers used a chemical analysis of the prints to determine whether a person had ingested cocaine. Currently, scientists are able to tell whether a person has touched cocaine based on their prints, notes Time, but the study in the journal Analyst takes the sleuthing a big step forward. Researchers predict that it could lead to portable tests for police departments within a decade. That's because "it's non-invasive, hygienic, and impossible to fake, with the identity of the subject captured in the fingerprint itself," explains Gizmag.
Researchers used a technique known as mass spectrometry to search for telltale signs of cocaine use in the prints. "When someone has taken cocaine, they excrete traces of benzoylecgonine and methylecgonine as they metabolize the drug, and these chemical indicators are present in fingerprint residue," explains the study's lead author, out of the UK's University of Surrey. One hurdle is developing small spectrometers to make such testing portable and cheap, and UPI reports that several companies already are working on it. (In a similar vein: A study figures out how rapists who wear condoms can be caught.)