Europium Ionic Liquid Grafted Covalent Organic Framework with Dual Luminescence Emissions as Sensitive and Selective Acetone Sensor

Chronical exposure to volatile acetone could damage to the liver and kidney or nerve, and cause inflammation. Design of novel materials for the sensitive and selective detection of acetone is of great importance. We report on a europium (Eu)-containing covalent organic framework (DhaTab-COF-EuIL) synthesized via a Schiff-base reaction between 2,5-dihydroxyterephthalaldehyde (Dha) and 1,3,5-tris(4-aminophenyl)benzene (Tab) followed by an ionic liquid (IL)-modification and then ion displacement. The resulting DhaTab-COF-EuIL is microporous and crystalline, and not only presents unique dual luminescence emissions of Eu³⁺ and COF material, but also exhibits remarkable luminescence quenching toward acetone. Especially, the DhaTab-COF-EuIL could be a novel luminescent sensor, displaying high sensitivity and selectivity for the detection of volatile acetone with a limit of detection down to 1%.