Colorimetric Array Detects Nerve Agents

A color-based array for detecting sarin, soman, tabun, and other chemical warfare agents is the first sensor that could allow people to distinguish between the different organophosphorus compounds at a glance, according to the Spanish research team developing the sensor (Chem. Commun., DOI: 10.1039/c2cc34662a). Because medical treatment for nerve gas exposure can differ depending on the agent, it’s important for emergency response teams to be able to quickly and easily distinguish among the toxic chemicals, says Ana M. Costero of the University of Valencia, in Spain. Costero and coworkers identified 16 dyes that change color when reacting with different functional groups found in nerve agents. They created a 4 × 4 array and showed that different color-change constellations produced when the sensor is exposed to nerve agent proxy compounds provide a way to classify the chemical warfare agents by eye. The test doesn’t give false positives for common airborne chemicals such as nitrous oxide, which is a particular challenge to sensor designers, Costero tells C&EN. “The main advantages are that the sensor is easy to use and cheap to produce,” she adds.