Tattoo Sticker for GHB Detection to Prevent Date Rape

In this study, we report the development of a wearable tattoo sticker designed for rapid and noninvasive detection of γ-hydroxybutyrate (GHB), which is commonly associated with drug-facilitated sexual assault (DFSA). The tattoo sticker for GHB detection utilizes a colorimetric sensor integrated into a tattoo-like patch that responds to the presence of GHB by changing its color, thus providing real-time monitoring and detection. The tattoo sticker comprised a polydimethylsiloxane (PDMS) film, 12 wt % poly(vinyl alcohol) (PVA) solution, and an agarose gel embedded with the chemical receptor 2-(3-bromo-4-hydroxystyryl)-3-ethylbenzothiazol-3-ium iodide (BHEI). BHEI is a chemical receptor whose color changes upon interaction with GHB. BHEI was added to an agarose gel to detect GHB. The agarose gel functionalized with BHEI (AGB) detected a small amount (5 μL) of the 0.01 mg/mL GHB solution. The tattoo sticker was fabricated by using the PDMS film, AGB, and PVA solution. Durability and stability of the tattoo stickers were evaluated through mechanical testing (twisting, stretching), environmental exposure (water resistance), and practical handling conditions (adhesion strength and scratch resistance). Additionally, the tattoo sticker detected the 0.01 mg/mL GHB solution as well as GHB at a concentration of 0.1 mg/mL in various beverages such as whisky, vodka, beer, soju, and coffee. Detection times of the GHB solution and beverages contaminated with GHB were within 1 s. A commercial tattoo sticker was used to replicate a real tattoo sticker. The GHB tattoo sticker was integrated with a tattoo sticker to reproduce the letters. Our GHB detection tattoo sticker can be used as a crucial tool in preventing DFSAs by offering a proactive solution for GHB detection and empowering potential victims to safeguard themselves.