Tim Hornyak/CNET

You may be wise enough not to leave your drink unattended if you go to bars or campus parties, but scientists in Israel can still help you ensure you don't get a nasty surprise in your mojito.

Fernando Patolsky and Michael Ioffe of Tel Aviv University's school of chemistry say they've developed a sensor that can tell you in real time whether your drink has been spiked with common date-rape drugs.

The sensor, which looks like a straw or swizzle stick, works by sucking up a small sample of the drink and mixing it with a testing solution that causes the stick to change color if drugs are present. A red light also goes on, so it can be used in the dark.

"The drug itself is reacting with this chemical formulation and the previously clear formula becomes dirty and when the light shines it you can detect it," Ioffe told AFP recently. "You don't have to do anything but dip it in your drink."

So far, the sensor has been 100 percent accurate in tests for GHB (gamma-hydroxybutyric acid) and ketamine, the researchers say. They are also trying to get it to work with Rohypnol, another common date-rape drug. All are colorless, odorless, and tasteless.

The sensor's chemical formula is inexpensive to produce and non-toxic, and the device could be commercially available within a year and a half. The scientists are looking for investors to help them market it.

They may change the way the danger is communicated to the drinker. For instance, the sensor could send a text to the user's phone to warn discretely about the presence of a drug.

Now that would sure be a mood killer.