EHU paper device turns color in about 10 minutes when a drink contains scopolamine

The design moves a color-forming reaction off the bench and onto paper. In the group's description, microfluidics shrinks or simplifies a laboratory process so the sample does not need to be handled at all. According to the release, that makes a preliminary analysis possible on site ^[14]. "Microfluidic technology opens the door to a type of analysis that was impossible before," said Isabel Poves, a predoctoral researcher with the group and the study's lead author ^[13][12].

The phys.org account does not report a detection limit, which beverages were tested, how many samples were run, or how often the device changed color with no scopolamine present. A drink test depends on those numbers. A visible color reaction reads yes above some concentration and no below it, so a drink spiked under that threshold comes back clean. The researchers say the prototype "can be refined according to user needs" ^[8].

Poves said the device "will help prevent drug-facilitated assault, because more important than detecting it after the fact is trying to prevent it from happening in the first place" ^[15]. I think that aim fits this drug. Few methods exist for detecting it quickly on site ^[7]. Prevention also puts the weight on the negative result. Someone who dips the device and sees no change will keep drinking. Its false-negative rate at the doses used in real assaults will decide whether it helps drinkers or only investigators. Until that is published, I would treat a positive as a reason to stop and send the sample for instrument analysis, the method with the established sensitivity and specificity ^[6].

The scopolamine device is one piece of a larger project. The group has already built a device for benzodiazepines in beverages with the same characteristics ^[9]. The project's aim is to detect as many drugs as possible with one device by building known color reactions into a single design ^[10]. "We are trying to adapt the colorimetric chemical reactions to microfluidic technology in order to simplify this type of detection, to lower costs, automate the process and, in particular, to be able to see with the naked eye a color change indicating that a beverage has been adulterated," said Basabe-Desmonts ^[11]. The release adds that existing smartphone apps that analyze color accurately could later read the result ^[16].