Naval Research Laboratory and Florida International University Advance Non-Contact Detection of Trace Fentanyl

WASHINGTON, D.C.  –   Scientists at the U.S. Naval Research Laboratory (NRL), working with Florida International University’s (FIU) Global Forensic and Justice Center, have demonstrated a new method for detecting trace levels of fentanyl using a silicon nanowire (SiNW) array that concentrates chemical vapors for handheld detection instruments. The breakthrough offers first responders a faster, safer way to identify fentanyl and related synthetic opioids without direct contact with the drug.

Fentanyl, a synthetic opioid roughly 50 times stronger than heroin, remains a leading cause of overdose deaths in the United States. Even trace amounts, as little as two milligrams, can be lethal if inhaled or absorbed through the skin. Current field methods for detecting fentanyl typically require handling bulk samples or destructive preparation, increasing the risk of accidental exposure and adding time to forensic analyses.

“Our sailors could come in contact with this substance, and it could possibly be used as a warfare agent. Having a detection method that’s readily available is important for protection,” said Ashley Fulton, Ph.D., chemistry researcher at NRL and principal investigator on the project.

The NRL–FIU team focused on developing a non-contact detection approach, a way to test for fentanyl without touching or handling it directly, to keep first responders safe. Instead of looking for fentanyl itself, they targeted a chemical marker the drug gives off in air called N-phenylpropanamide (NPPA), a tiny by-product molecule that forms as fentanyl breaks down and acts like a unique “fingerprint.”

The team used a sampling method called solid phase microextraction (SPME). A special fiber essentially “soaks up” trace chemicals from the air and a gas chromatography–mass spectrometry (GC-MS), a lab instrument that separates and identifies molecules, and analyzes those vapors. The method proved that NPPA is a reliable vapor signal for fentanyl and its close relatives. They then fine-tuned a portable ion mobility spectrometer (IMS), a handheld detector that measures how charged particles move through gas, so it could recognize the NPPA signal at amounts as small as five nanograms (about five-billionths of a gram) without being tricked by common drug fillers such as mannitol, lactose, or acetaminophen.

To further enhance sensitivity, the team integrated a silicon nanowire preconcentration array coated with an acrylate-based polymer. This configuration increased NPPA detection up to 14-fold in laboratory testing and maintained performance even in the presence of street-level adulterants. The silicon nanowire device adsorbs target vapors and then releases them as a concentrated pulse, allowing handheld detectors to register previously undetectable trace amounts.

“This work demonstrates a promising path toward rapid, non-contact detection of fentanyl that could help protect law enforcement officers, customs officials, and emergency responders,” Fulton said. ““Fentanyl is a highly potent drug that can cause overdose at very, very low concentrations. Law enforcement officers often feel high anxiety when they encounter unknown substances. This technology gives a preventative, presumptive identification so the proper care can be taken at the scene of a crime.”

Field tests with confiscated fentanyl samples from the Drug Enforcement Administration and Maryland State Police laboratories confirmed the method’s ability to detect NPPA in high-purity samples and complex street mixtures.

“The next step is demonstrating the full capability of the silicon nanowire system for trace detection,” Fulton said. “Our goal is to have a prototype ready by the end of 2026.”

This research was supported through an Interagency Agreement with the National Institute of Justice, Office of Justice Programs and the U.S. Department of Justice.

About the U.S. Naval Research Laboratory
NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL, located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California, and employs approximately 3,000 civilian scientists, engineers and support personnel.
 
NRL offers several mechanisms for collaborating with the broader scientific community, within and outside of the Federal government. These include Cooperative Research and Development Agreements (CRADAs), LP-CRADAs, Educational Partnership Agreements, agreements under the authority of 10 USC 4892, licensing agreements, FAR contracts, and other applicable agreements.
 
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