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.