Dual-Emitting Eu(III)–Cu(II) Heterometallic–Organic Framework: Simultaneous, Selective, and Sensitive Detection of Hydrogen Sulfide and Ascorbic Acid in a Wide Range

As
important biomolecules, the deficiency or maladjustment of hydrogen
sulfide (H2S) or ascorbic acid (AA) is associated with
the symptoms of the same disease (e.g., cardiovascular disease or
cancer). There is an urgent need to develop a fluorescent probe capable
of distinguishing between H2S and AA simultaneously. Here,
we report the syntheses, structure, and property of the first dual-detection
fluorescent probe which can differentiate H2S or/and AA
in aqueous media. Accordingly, a novel [EuCu­(pydc)2(ox)0.5(H2O)3·1.5H2O]2n (1, H2pydc = 2,3-pyridinedicarboxylic
acid and ox = oxalic acid) for selective and sensitive detection of
H2S and AA in a wide range has been constructed (H2S: [130 nM, +∞); AA: [55 nM, +∞)), exhibiting
excellent catalytic activity comparable to horseradish peroxidase.
In addition, the highly efficient detection in human serum sample
also proves the potential application in medical diagnosis. Meanwhile,
a combinatorial logic gate (AND­(INH)–OR) based on activated 1 has also been constructed. Furthermore, this approach for
simultaneous H2S and AA detection suggests that the current
work will expand the potential application of metal–organic
frameworks for dual or multiple detections in biomedical fields.