Six new lanthanide metal–organic frameworks as luminescent sensors for the detection of 1-N, TDGA, UA, and HA in urine

The hydrothermal reaction of Ln(NO3)3·6H2O with H2tyia (H2tyia = 5-(triazol-1-yl) isophthalic acid) afforded the lanthanide organic frameworks (Ln-MOFs), [Eu2(tyia)3(H2O)3]n (1) and {[Ln2(tyia)3·(H2O)3]· 3H2O}n (Ln = Tb 2, Dy 3, Sm 4, Gd 5, and Nd 6). Compounds were characterized by routine methods: PXRD, elemental analysis, solid-state luminescence properties analysis, TGA, FT-IR, and single-crystal X-ray crystallography. In this work, the luminescent properties of 2, 4, 5, and 6 and the responsiveness of various chemical components contained in urine were investigated. These MOFs detect 1-naphthol (1-N), urinary thiodiglycolic acid (TDGA), uric acid (UA), and hippuric acid (HA), which are the final metabolites of carbaryl, vinyl chloride monomers, purine, and toluene, respectively. These new Ln-MOFs offer the potential for biomarkers or metabolic sensors and show excellent selective and sensitive luminescence detection of 1-N, TDGA, UA, and HA.