A temporary tattoo sticker developed in South Korea could help to promptly detect date rape drugs.
Date rape drugs are substances that are very hard to detect because they have no distinguishable flavour, odour or colour. Perpetrators lace alcoholic or soft drinks with them in order to make their victims lose consciousness, then sexually assault them.
One of the main date rape drugs is GHB, or gamma-hydroxybutyric acid. It can lead to a stuporous state similar to acute alcohol intoxication and also cause temporary memory loss.
People can check if their drinks have been spiked with GHB using paper test strips and other single-use products that change colour when they come into contact with it. However, they take a number of minutes to react and they are conspicuously large, which makes them difficult to use, especially in dangerous situations.
Researchers from the Department of MetaBioHealth at Sungkyunkwan University in Suwon have tackled this problem by developing a temporary tattoo sticker that gives reliable results in just one second, meaning it can be genuinely helpful for anyone who thinks their drink has been spiked. What’s more, the colour change lasts for at least a month, thus providing evidence for investigators.
As illustrated in the scientific journal ACS Sensors, the temporary tattoo features a plastic film decorated with one of a number of designs resembling permanent tattoos (so as not to reveal its true nature). Inside it is a hydrogel blend containing a mixture that turns red if it comes into contact with GHB. On the other side of the film is a diluted glue solution that ensures the tattoo remains attached to the skin.
The researchers tested the tattoo’s reliability by dipping it into small amounts of alcoholic drinks such as whisky, vodka, beer and soju (a Korean beverage), as well as coffee. They showed that it takes just a second to detect GHB at extremely low concentrations, even below the level that could be dangerous: 0.01 micrograms per millilitre of liquid. This means that a tattoo wearer could dip a finger into a drink they think might have been spiked, let a drop fall onto the sticker and find out immediately, without attracting attention. In addition, as mentioned above, the colour change remains stable for at least a month: this could prove crucial in the event of assault and during the subsequent criminal procedure.
According to the Korean researchers, the tattoos are extremely cheap and easy to manufacture. They can also withstand exposure to mechanical stress and water. If they were made commercially available (which the researchers hope will happen soon), bar owners could provide them for their customers and people could also buy their own and wear them if they expect to find themselves in potential risky situations.