South Korean researchers from Chung-Ang University, Pohang University of Science and Technology, University of Science and Technology and Korea Institute of Materials Sciences (KIMS) have created a wearable sensor that rapidly detects illegal drugs present in sweat via nanomaterial technology.

According to developers, the sensor uses surface-enhanced Raman scattering technology to enhance the Raman signal of chemical substances, including narcotics, by 10¹⁰ and even more.

Source: Korea Institute of Materials Science (KIMS)

To develop the wearable optical sensor, researchers extracted a silk fibroin protein from a silkwood cocoon to create a 160 nm thick film, which was then coated with 250 nm thick silver nanowire and attached to a medical-grade patch.

Adhered to the skin, the patch absorbs sweat and the drug substance within the wearer’s sweat penetrates the sensor, reaching the silver nanowire. The patch is then irradiated via the Raman laser, revealing the presence of the drug.

According to the developers of the patch, this process can be done in approximately one minute — much quicker than traditional drug testing approaches such as blood and urine testing wherein biological specimens are tested in a lab setting.

Additionally, the sweat patch testing reportedly avoids the ethical issues that potentially arise from conducting drug testing via urine samples where subjects are observed as they provide samples.

The research appears in the journal ACS Applied Materials and Interfaces.