A new wearable sensor uses nanomaterials technology to detect illicit drugs in sweat

Researchers in South Korea have developed an accessible sensor that detects illegal drugs in sweat by using nanomaterials technology that expands the optical signal of narcotics into a flexible, body-wearing material. Directed by Dr. Ho Sang Jung, the research unit is part of the Korea Materials Science Institute (KIMS), a government-funded research institute under the Ministry of Science and ICT.

The technology enables rapid and highly sensitive detection of drugs: the sweat patch is attached to the skin for a specific period of time and then irradiated with light for testing. It only takes one minute without the need for additional processing.

The traditional drug detection process requires a complex method for extracting suspected drug components from biological samples including hair, blood, and urine, and then making drug analysis by gas or liquid chromatography mass spectrometry (GC / MS or LC / MS). It takes longer test time and requires a large room for the instrument and skilled technicians. Although rapid devices detect drugs in urine, they detect only one component in a single test and have low sensitivity.

For athletes, anti-doping drug testing will be performed to detect banned substances in blood and urine. Blood tests are often avoided because of concerns about a decline in athletic performance, and a urine test can violate human rights because the tester must observe the athlete’s dignity. For the major sporting events such as the Olympics, it is difficult to test all the participants.

The researchers focused on sweat that is non-aggressive and relatively free of human rights issues. However, very few substances are released in sweat, even though several drugs are taken in sweat so a highly sensitive sensing technology needs to be developed for better detection.

The team’s highly sensitive sensor was using Raman scattering technology with a surface capable of increasing the Raman signal of chemicals 1010 times and more. Because the Raman scattering signal includes the specific signal of molecules, identification of intuitive substances is possible regardless of which drug is released.

The researchers focused on the cocoon protein, a flexible wearable material to improve accessible optical sensing. Silk fibroin solution, a natural protein, was extracted from a silkworm cocoon to form a 160 nanometer (nm) thick film. The film was coated with a 250 nanometer (nm) silver nanowire and transferred to the medical area that can be attached to the skin.

As soon as the patch absorbs the swab, the drug substance in the swab enters the accessible sensor and reaches the silver nanowire. By irradiating a Raman laser on the patch, the drug can be detected in real time without removing the sensor.

This technology can help address social problems such as drug circulation and celebrity-related abuse, drug dealing in clubs, and the banned substances taken by athletes. Since the production cost is less than 50 cents per piece, it can be used for an anti-doping program as a complete numeracy study at major sporting events such as the Olympics.

As can be seen in recent drug-related crimes, Korea is no longer a drug-free country. The improved technology would overcome the technological limitations of drug identification and the use of prohibited substances and enable drug detection without aggressive and ethical problems. “

Dr. Ho Sang Jung, Director, Research Unit, National Science & Technology Research Council

This work was supported by the Korea Institute of Materials Science (KIMS) Basic Research Program and funded by the Ministry of Science and ICT (MSIT). The article explaining results was published in ACS Applied Materials and Interface, a world-renowned academic journal on January 6, 2021. The technology was patented in South Korea and filed for U.S. patent.

Based on this project, the researchers are actively developing accessible healthcare sensors that allow rapid testing of disease-related metabolites.