Rapid visual detection of nitroaromatic explosives using a luminescent europium-organic framework material

Rapid field screening is enormously important in forensic analysis of explosives. In this article, we used a methodology based on a strong red-fluorescent europium-organic framework (Eu-MOF) material for sensitive and selective detection of picric acid, TNT, and tetryl using the fluorescence quenching effect. Results indicate that Eu-MOF can be used for the visual detection of these three explosives with low detection limits (20-140 μg/mL) and high quenching efficiency (Ksv > 10⁴ M^-1). Furthermore, this material can be recycled just by washing it with ethanol. The fluorescence quenching mechanism is also discussed. Importantly, we prepared a portable test strip that can be used for sensing TNT, and using this, we achieved a rapid field test for explosives. Consequently, Eu-MOF is a promising candidate material for use as an explosive optical sensor.