A dual‐function Cd‐based coordination polymer for the detection of moxifloxacin and SiO32− ions

A 1D coordination polymer (CP) [Cd2L2(H2O)4] ⋅ 3H2O (1) was prepared by solvothermal method using 1‐(4‐carboxyphenyl)‐1H‐pyrazole‐3‐carboxylic acid (H2L) as single ligand. Fluorescence sensing experiments show that 1 has dual‐function specific recognition ability for moxifloxacin (MXF) and silicate (SiO32−), which can be used as the turn‐off sensing material for their detection. When 1 specifically identifies MXF, the Ksv is as high as 6.46×105 M−1 (6–20 μM) and the limit of detection (LOD) is as low as 14 nM. 1 is the second example of a CP‐based fluorescent probe for the detection of MXF, which has confirmed that the Ksv is the largest to date for the detection of MXF, with a detection sensitivity increase of more than three times. For SiO32− ions detection, the fluorescence intensity ratio has a good linear correlation with the concentration of SiO32− ions in the concentration range of 0–100 μM, with a slope of 1.33×104 M−1, and the LOD is as low as 0.68 μM. According to the reported literature, 1 is the only example of SiO32− ions sensing by CP‐based fluorescence sensor so far. In order to better understand the sensing phenomenon, we also discussed the sensing mechanism for MXF and SiO32− ions. H2L (L=1‐(4‐carboxyphenyl)‐1H‐pyrazole‐3‐carboxylic acid) and Cd2+ ions were self‐assembled by solvothermal method to prepare the coordination polymer 1 with 1D chain structure. 1 has dual‐channel specific recognition ability for moxifloxacin (MXF) and silicate (SiO32−), which can be used as the turn‐off sensing material for their detection. 1 is currently the second CP‐based fluorescent sensor for MXF detection, and has the best sensing performance, with a sensitivity increase of more than three times. At the same time, as the first CP‐based sensor material for detecting SiO32−, 1 shows excellent sensing properties and the limit of detection (LOD) is 0.68 μM.