J. Am. Chem. Soc. doi:10.1021/ja809104h (2009)

Despite recent advances, detecting trace explosives in a simple, portable and low-cost manner is a challenge. Jinghong Li of Tsinghua University in Beijing, Nongjian Tao of Arizona State University in Tempe and their colleagues have now created an effective sensing platform.

Their device uses an ionic liquid to pre-concentrate the explosives, electrochemical reactions to generate reaction products that absorb in the visible spectrum, and colorimetric methods to detect them. The authors tested the platform's power in detecting compounds such as TNT or picric acid down to a few tens of parts per trillion. The platform can distinguish these from potential red herrings such as vapour-producing household chemicals and personal care products.