Uranyl Organic Framework as a Highly Selective and Sensitive Turnon and Turn-off Luminescent Sensor for Dual Functional Detection Arginine and MnO4-

Five new uranyl coordination polymers were prepared by the hydrothermal method based on 5-nitroisophthalic acid (H(2)nip) as (UO2)(nip)(2,2'-bpy) (1), (H(2)4,4'-bpy)center dot[(UO2)(3)(nip)(4)]center dot(4,4'-bpy) (2), (H(2)bpe)center dot[(UO2)(0.5)(nip)] (3), (H(2)bpp)center dot[(UO2)(2)-(nip)(3)]center dot H2O (4), and (H(2)tmp)center dot[(UO2)(nip)(2)](5) [2,2'-bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'bipyridine, bpe = 4,4'-vinylenedipyridine, bpp = 4,4' -trimethylenedipyridine, tmp = tetramethylpyrazine]. All of these synthesized complexes have been characterized by single crystal and powder X-ray diffraction, IR spectra, thermogravimetric analysis, elemental analysis, and luminescent properties. In particular, it is found that compounds 1 and 4 can be used as a luminescent sensor to efficiently detect arginine in aqueous solution by means of turn-on; the detection limits were 1.06 X 10(-6) and 6.42 X 10(-6) mol/L, respectively. Moreover, 4 can also be used as a bifunctional sensor for selective sensing of MnO4- anion by turn-off. The detection limit of MnO4- in water was 1.79 x 10(-6) mol/L; the Ks, was 1.88 X 10(4). The sensing effect of arginine in simulated grape juice samples and MnO4 in simulated river water samples was also investigated by this sensing system with high recovery. In addition, the possible mechanism of sensing arginine and MnO4- in the aqueous solution was discussed.