'Date rape' sensor identifies spiked drinks

Posted by Emma Woollacott

Tel Aviv University researchers have developed an anti-date rape device that can detect whether a drink's been spiked and warn the victim.

The team says the sensor can detect GHB and ketamine - the most commonly used date rape drugs - with 100 percent accuracy. When it's ready for commercial purchase in a few years' time, they say, it will be lightweight and discreet, easily transportable in a pocket or purse.

According to the US Department of Justice, some 200,000 women were raped in the US in 2007 with the aid of a date rape drug — and because so many cases go unreported, the actual number is believed to be 80 to 100 percent higher.

Until now, though, no sensor sensitive enough to detect the drugs had been developed. And after a few hours, the drugs become undetectable in the human bloodstream, making their presence difficult to prove.

The new system works on simple optics principles. Though date rape drugs are colorless, they do subtly change the optical properties of a drink. When a ray of light comes into contact with a drugged drink, a 'signal change' occurs and the sensor sounds the alarm.

It's not often that bartenders need to be recruited for scientific studies, but the team hauled some in to prepare a large number of the 15 most popular cocktails.
 
Fifty of these drinks were randomly spiked with GHB - and, when the test was conducted, every one was correctly identified, with no false positives.

Only a tiny 'sip' of one to ten microliters is required for the sensor to detect the presence of a date rape drug.

The team's now working on miniaturizing the system. Each device might look like a pen or clip - easy to dip into a glass. A disposable cartridge inside would be able to identify two to three spiked drinks before needing to be replaced — and new cartridges would each cost under a dollar.

The team is also hoping to widen the range of drugs that the sensor can correctly identify.

"Currently, the system is geared towards detecting GHB and ketamine," says Dr Michael Ioffe. "We hope to expand the system so it will identify additional date rape drugs as well."