"We can use this bracelet as a protection method and make a concert, festival, or nightclub a safe place, because people can protect themselves with this system," Carlos Lodeiro Espiño, from the Faculty of Science and Technology at NOVA University Lisbon (NOVA FCT), told Lusa.

According to the project coordinator in Portugal, this bracelet is already sold in Spain and can be purchased in Portugal on the website of the startup Nanoarts, but the intention is for it to also be made available through event organizers or public entities, such as city councils.

In practice, it's a sensor embedded in a paper bracelet that reacts directly to any drink containing one of the three "date rape drugs": GHB, the cheapest and easiest to obtain, burundanga, imported from Latin America, and cathinones, explained Carlos Lodeiro Espiño.

According to the researcher, GHB, the most commonly used drug in cases of chemical submission, is a drug that, a few hours after ingestion, "cannot be detected in urine, blood, or saliva," thus requiring a "rapid device to detect" its presence.

"It's immediate and serves as a preventative and deterrent," Carlos Lodeiro Espiño added, warning that GHB is a substance that, in the past, was used in medicine as an anesthetic, causing a person to "be unable to react" and also suffer an episode of amnesia a few hours after ingestion.

Emphasising that this substance has no smell, colour, or taste, the researcher added that with the new bracelet, "someone going to a nightclub, a festival, or an outdoor concert who wants to test any drink before drinking it can simply touch the straw to the bracelet" and check for a colour change to green.

For a 60-kilogram woman, two to three grams of the drug are enough to result in her chemical submission, Carlos Lodeiro Espiño emphasised.

The researcher gave the example of the autonomous community of Valencia, in southern Spain, which the researchers consider to be a prototype laboratory, where "there has been a significant drop in rape and attempted rape cases," by at least half.

The project, developed in collaboration with the University of Valencia and the company Celentis, has already resulted in a joint patent and scientific articles, and the researchers are now working on a system that allows this sensor to be considered forensic evidence in the event of potential crimes.

The investigation team is in contact with authorities to ensure the bracelet can be recognized as legal evidence, as well as with municipalities and event organizers in Portugal to ensure it can be integrated into awareness and prevention campaigns.

"We want [the test result] to be unaltered by anyone because, to serve as forensic evidence, we must ensure that no one can change the result," explained the investigator.

"Our goal is to offer a simple, accessible, and effective tool to prevent sexual abuse crimes, especially in contexts where people are more vulnerable, such as nightclubs, bars, or festivals," concluded the full professor in the Chemistry Department at NOVA FCT.