A new Tb(III)-functionalized layer-like Cd MOF as luminescent probe for high-selectively sensing of Cr3+

A new layer-like metal-organic framework {[Cd4NDIC)(4)center dot 5DMF center dot H2O]DMF}(n) (NDIC = 5-(5-norbonene-2,3dicarboximide) isophthalic acid) was synthesized by solvothermal method. It was used as a parent framework to encapsulate Tb3+ cations in Cd-MOF. The obtained composite Tb(3+)@Cd-MOF exhibited excellent luminescence and produced a remarkable quenching effect in the luminescence emission of Tb3+ upon the introduction of Cr3+. Subsequently, Tb(3+)@ Cd-MOF was developed as a highly selective and sensitive probe for detection of Cr3+. In particular, the luminescence probe of Cr3+ had a low detection limit (7.5 x 10(-8) M), a broad linear range (1 x 10(-7) -5 x 10(-6) M). A paper strip coated with Tb(3+)@Cd-MOF was also shown to be highly selective to Cr3+ under the irradiation of 254 nm UV light of by the naked eyes. This is the first example for detecting metal ions based on a lanthanide functionalized new metal-organic framework (MOF).