A highly sensitive and selective Cd-MOF fluorescent probe for the detection of His, NB, TC and PTH and its applications in real samples

A novel metal-organic framework (MOF) with the formula of [Cd(CIA)(4,4 '-BB)center dot H2O]center dot H2O (Cd-MOF) (H2CIA = 5-methoxyisophthalic acid, 4,4 '-BB: 4,4 '-bis((1H-imidazol-1-yl)methyl)-1,1 '-biphenyl) has been designed and synthesized through solvothermal reaction. The structure was characterized by TG, IR, PXRD, elemental analysis, single-crystal X-ray diffraction and XPS. The coordination pattern of the fully deprotonated ligand (CIA) in CdMOF is mu 2-k1: k0: k2. The complex is found to be a three-dimensional reticular material with good thermal stability. Further study revealed that Cd-MOF has good fluorescence performance and can be used as a fluorescent probe for sensitive detection of histidine (His), nitrobenzene (NB), tetracycline (TC) and pyrimethanil (PTH) in water. Four cycles experiments can be achieved with a low detection limit. The detection limits were 0.3 mu M (His), 0.05 mu M (NB), 0.2 mu M (TC) and 0.01 mu M (PTH), respectively. To verify the feasibility of detecting PTH in real samples, we further explored it in water samples and apple peels. The spiked recoveries were 95.3-99.4 % and 97.2-101.2 %, respectively. Finally, the fluorescence quenching mechanism of Cd-MOF in His, NB, TC and PTH detection is discussed in detail.