In forensic laboratories, drug identification often begins with color tests—quick and cost-effective methods that change color in the presence of drugs. However, these tests have limitations; they are non-specific and may not precisely identify the drug involved, often requiring additional testing for confirmation.

For nearly two decades, the National Institute of Justice (NIJ) has funded research to enhance drug detection and identification. Dr. Luis Arroyo, an associate professor in the Department of Forensic and Investigative Science at West Virginia University, has recently advanced this mission with a study supported by the NIJ.

Dr. Arroyo’s research explores the use of advanced electrochemical techniques to detect emerging drugs, such as fentanyl and novel psychoactive substances, in seized drug cases. These techniques, which are widely used in biomedicine, chemistry, and environmental sciences, were validated through Raman spectroscopy—a non-destructive method that provides a structural fingerprint of unknown substances. The study suggests that combining these methods could significantly enhance current drug screening procedures.

Using Carbon Electrodes for Drug Detection

The team at West Virginia University aimed to develop more informative and cost-effective drug testing techniques, adhering to current forensic laboratory standards, and potentially applicable both in laboratories and in the field. They successfully used screen-printed carbon electrodes, which utilize electrical conductivity to detect and identify drugs. Additionally, the team evaluated the effectiveness of portable Raman spectroscopy for drug identification. The combined use of these electrochemical sensors and Raman spectroscopy improved the overall identification accuracy of fentanyl and its analogs to 87.5%, a significant improvement over traditional color tests.

Dr. Arroyo highlighted the advantages of these techniques, including their versatility, selectivity, sensitivity, minimal sample preparation, speed, low cost, robustness, and portability—attributes that make them suitable for both laboratory and field use.

Implications for Forensic Practice

Beyond the faster results, Dr. Arroyo emphasized the critical information gained through these methods. “Being able to identify fentanyl in complex mixtures and distinguish between its analogs is a truly remarkable achievement,” he said.

Although many forensic laboratories still rely on color tests, Dr. Arroyo’s research showcases the superior capabilities of electrochemical sensors, paving the way for their adoption in both field and laboratory settings.

“While these methods are not new in analytical and forensic chemistry, they have yet to be widely adopted in forensic drug testing,” Arroyo noted. “This research could facilitate the integration of these innovative sensors into mainstream forensic practices, streamlining both field and laboratory drug testing processes.”

National Institute of Justice, “What’s That Drug? Fast Screening of Seized Drugs,” August 5, 2024, nij.ojp.gov: https://nij.ojp.gov/topics/articles/whats-drug-fast-screening-seized-drugs

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