The press went crazy jumping all over a report that four North Carolina students invented a nail polish to detect "date rape" drugs. Just dip a finger into a drink, and watch for a colour change that is indicative of the beverage having been doctored with rohypnol, Xanax or gamma hydroxybutyrate, the classic date rape drugs. At least so goes the story.. Actually, the nail polish doesn't yet exist, it is just a concept. It is, however, a legitimate idea, given that test strips, coasters, straws and even glasses that change colour in response to the presence of certain drugs do exist.
The chemistry here is fascinating but very complex. It is based on a polymer which is cross linked after being treated with the drug that is to be eventually detected. The drug forges a space in the polymer matrix according to its molecular shape. It is then washed out leaving a cavity in the shape of the drug molecule. The same drug is then coupled to a dye and is added to occupy the spaces that have been vacated. When the polymer, which in theory could be incorporated into nail polish, is then dipped into a beverage, should any of the same drug be present, it will displace some of the the embedded molecules which after being bumped out release the dye that was attached.
Just how well the technology works still has not been properly established. There are many substances such as juices or milk that can interfere with the reaction.Furthermore there is a whole host of other potential date rape drugs like ketamine, zolpidem, barbiturates, chloral hydrate, opiods and phencyclidine that would not be detected. And of course the most widely used date rape drug is alcohol. Then there is also the issue that such products suggest that it is a potential victim's responsibility to detect the presence of a drug. As is far too common, press reports have been far too zealous in hyping this "invention."
