A sensor for detecting toxic gases is now smaller, faster and more reliable. Its performance sets it up for integration in a highly sensitive portable system for detecting chemical weapons. Better miniature sensors can also rapidly detect airborne toxins where they occur, providing key information to help emergency personnel respond safely and effectively to an incident.

Chemical identification typically involves collecting a sample at the scene of a chemical release and bringing it back to a room full of equipment operated by trained personnel. The machines sift through a sample of various gases and weigh the molecules to determine their identities. And while portable versions of these instruments, known as mass spectrometers, are commercially available, they are less sensitive than their lab-based counterparts.

For more than 20 years, researchers at Sandia National Laboratories have been working to avoid the performance penalty for portable gas detection. Their sensors employ a technique called gas chromatography, or GC for short.

Briefcase-sized instruments from Sandia have sniffed for nerve and blister agents continuously for 22 months in the Boston subway without a false alarm. Sensors about the size of a AA battery can detect a compound in sweat that signals smuggled humans. Handheld gas sensor systems can also monitor crop health by identifying gases that plants release when stressed by drought or sickness.

Read more: Portable gas detection shrinks to new dimensions