A luminescent Ln-MOF thin film for highly selective detection of nitroimidazoles in aqueous solutions based on inner filter effect

A luminescent mixed matrix membranes (MMMs) was synthesized by mixing 502 glue of the evo-bond brand (EVOB) and {Eu-2(TDC)(3)(CH3OH)(2 center dot)(CH3OH)}(n) micro-powder (Eu-TDC, where TDC is thiophene-2,5-dicarboxylate). The as-fabricated Eu-TDC MMMs has good stability and exhibits characteristic red emission of Eu3+ in aqueous solutions. The Eu-TDC MMMs as a sensor can efficiently detect nitroimidazole antibiotics (NIABs) in aqueous system due to its excellent luminescent stability. Significantly, the Eu-TDC MMMs is not affected by the other antibiotics or ions when detecting NIABs in original water, and shows lower limits of detection (0.58 mu g mL(-1) for metronidazole and 0.51 mu g mL(-1) for dimetridazole) with a wider linear range. The possible response mechanism based on inner filter effect is discussed in detail. What's more, the membrane sensor can be handily reused only by immersed in tap water with bare luminescence intensity loss, demonstrates an unusual instant reusable performance with simple recover method. This lanthanide complex luminescent MMMs sensor will be expected to application in detecting NIABs in biological and environmental systems.