Electroanalytical Sensing of Date Rape Drugs

This article reviews the current advancements in electroanalytical methods for the rapid, on-site detection of date rape drugs (DRDs) in beverages. DRDs are a broad category of chemical substances with sedative properties, commonly including benzodiazepines (BDZ), ketamine, gamma-hydroxybutyric acid (GHB), fentanyl, and various new psychoactive substances (NPS). The detection of these substances is crucial for preventing drug-facilitated crimes (DFC), particularly drug-facilitated sexual assaults (DFSA), where victims often experience amnesia or fear reporting. Most of the research in this area has been published within the last decade, emphasizing the urgent need for quick and accessible detection methods.

The review highlights electroanalytical sensing as a promising technology due to its low cost, simple configurations, and compatibility with modern portable devices like smartphones. This makes it ideal for “plug-and-play” scenarios, enabling non-expert users to obtain binary read-outs. The research primarily focuses on the detection of DRDs in real samples such as soft and hard drinks, though some work also covers body fluids.

Key findings and trends identified in the review include:

• Benzodiazepines (BDZ) are the most extensively studied and utilized DRDs across all media, including beverages. This is partly due to their strong sedative nature and short lifespan, making them ideal for DFC. Electrochemical detection of BDZs often leverages their electrochemically active functional groups, enabling detection via techniques like voltammetry and potentiometry.
• The electrochemical behaviors of many New Psychoactive Substances (NPS) are not yet well-characterized or studied in beverage media, indicating a significant gap in knowledge.
• Gamma-hydroxybutyric acid (GHB) is the least studied DRD in any sensing matrices due to its poor electrochemical behavior. GHB is particularly challenging because it is colorless, odorless, highly soluble in water and alcohol, rapidly eliminated from the body, and not electrochemically active under normal conditions.
• The development of wearable, printed lab-on-chip sensors is appealing and shows significant promise for practical, on-the-spot DRD screening in beverages. Examples include 3D-printed wearable “e-fingers” for multi-drug detection (like Flunitrazepam and Ketamine) and glove-based sensors for fentanyl.

Despite these advancements, significant challenges remain, including the analytical complexity posed by the diverse chemical composition of beverages, which can lead to interfering electrochemical signals or electrode fouling. There is an ongoing need for innovative electrochemical systems that minimize sample volume, preparation time, and testing steps to achieve truly practical on-site screening. The review concludes by emphasizing the need for further research into the electroanalytical behavior of GHB, morphine, and other NPS in beverages to address the existing knowledge gaps and improve rapid, presumptive detection methods.

Reference:

Balamurugan, T. S. T., Kwaczyński, K., Rizwan, M., & Poltorak, L. (2024). Current trends in rapid electroanalytical screening of date rape drugs in beverages. Trends in Analytical Chemistry, 175, 117712. https://doi.org/10.1016/j.trac.2024.117712