UT Dallas bioengineering researchers Ivneet Banga and Anirban Paul demonstrate how a sensor their team developed can detect fentanyl. The researchers drop liquid directly on the sensor platform, which is connected to a laptop and provides results within seconds. Credit: The University of Texas at Dallas
Forensic laboratories have been working hard over the past decade to eliminate the rape kit backlog. Many labs have, or if they have not, they are close to doing so or at least have measures in place to get there.
Unfortunately, forensic lab professionals have a second backlog on their hands that is negatively affecting turnaround time—drug analysis, thanks to the ongoing opioid crisis.
In a new study, researchers outline the development of a first-of-its-kind, handheld electrochemical sensor that can accurately detect fentanyl in urine within seconds.
“There is an urgent demand for an easy-to-use, portable, miniaturized device that can detect fentanyl with high specificity and share results immediately,” said corresponding author Shalini Prasad, professor and department head of bioengineering at the University of Texas at Dallas.
The device contains an electrochemical sensor, which generates electrical signals based on chemical reactions. Developing a sensor to detect fentanyl was a challenge, however, because the synthetic opioid is a nonvolatile compound, which means it does not produce an electrochemical signature. The researchers turned to a molecular cage-like structure—one they compared to a mousetrap.
The “trap” comprises several substances, including gold nanoparticles. Meanwhile, the “cheese” is naloxone. Prasad and colleague Anirban Paul, first author of the paper, conducted computational tests to understand how the compounds interact so they could determine how to deploy naloxone to draw fentanyl to it like a magnet.
“[We use] naloxone to capture fentanyl, like cheese to catch a mouse,” said Paul.
For the study, published in ACS Applied Materials & Interfaces, Prasad and Paul tested urine samples spiked with low, medium and high levels of fentanyl using their new electrochemical sensor. If the drug was present, the naloxone interacted with it, generating a signal. The study results show the device detected fentanyl up to 100 parts per million in the spiked urine samples at a rate of 98% accuracy.
The technology also could be used to test substances for fentanyl by mixing a sample with water and dropping the liquid onto the sensor.
The proof-of-concept device is a step toward portable—or even in-lab—detection without traditional costly and time-consuming analysis.
The researchers say the prototype is a stepping stone to detecting fentanyl in other matrices. They are already working to advance the technology to detect fentanyl in hair, with the ultimately aim to develop a detect to detect the opioid in saliva.
Prasad and her team are well-versed in this area of research. They have already developed a variety of electrochemical sensors to detect biomarkers of infections in sweat, including for COVID-19, as well as biomarkers for flare-ups of inflammatory bowel disease. Last year, they developed a test to measure THC in saliva with 94% accuracy.