Fentanyl kills. Make that: Fentanyls kill. The threat is plural and potent, as illicit laboratories continually concoct new forms of the drug that sidestep today's best detection techniques and protect drug dealers from prosecution.

It's a loophole that drug dealers are quick to step through—creating new drugs faster than the law and health care providers can keep track of them. While emergency responders are on the front lines daily in an epidemic that has seen hundreds of thousands of American lives lost, they have allies in chemists at the Department of Energy's Pacific Northwest National Laboratory. PNNL scientists are developing ways to detect and identify not only new, previously unseen forms of fentanyl but also newer and more dangerous synthetic opioids known as nitazenes.

The PNNL team has hurdled a key barrier in the detection of other forms of fentanyl, known as fentanyl analogs, and nitazenes. Most current detection methods rely on libraries of known compounds that have already been seen and reported. When responders encounter a substance suspected of being fentanyl, either the material is tested chemically or compared to known fentanyls in a database.

If there's a match, authorities know they've got a fentanyl compound. But there are many potential fentanyl analogs; PNNL chemist Katherine Schultz has calculated that billions are possible. That's fertile ground for chemists tinkering in illegal laboratories around the world.

Once a known fentanyl form has been c.