A Eu‐Doped Y‐Based Luminescent Metal–Organic Framework as a Highly Efficient Sensor for Nitroaromatic Explosives
By an isomorphous substitution strategy, a three-dimensional metal–organic framework (MOF), [Y1.8Eu0.2(PDA)3(H2O)1]·2H2O (1; PDA = 1,4-phenylenediacetate), has been synthesized by solvent-assisted liquid grinding and direct heating. Dehydrated 1 (1′) shows strong red photoluminescence through the antenna effect upon excitation at 240 nm. The red emissive property was used for the visual detection of nitroaromatic explosives in acetonitrile through luminescence quenching. Importantly, 1′ exhibited high sensitivity towards the sensing of 2,4,6-trinitrophenol (TNP), 1,3-dinitrobenzene (DNB), 2,4-dinitrotoluene (DNT), 4-nitrotoluene (NT), and nitrobenzene (NB) at very low concentrations (0 to 20 μM). The estimated KSV (quenching constant based on linear Stern–Volmer plots) values are in the range 15.9 × 104–1.1 × 104 M–1, which are amongst the highest values known for nitroaromatic-sensing materials. For 1′, sensing of TNP down to 23 ppb has been achieved.