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

Cd-MOF fluorescence sensor was synthesized by hydrothermal method using carboxylic acid and imidazole. The sensor not only has good stability under different pH conditions, but also has high sensitivity, selectivity, anti-interference and circulation ability for His NB TC and PTH. It is particularly significant that the sensor can effectively detect pesticides in peel and Yanhe River water. [Display omitted] • A new type of Cd-MOF ([Cd(CIA)(44′-BB)·H 2 O]·H 2 O) was synthesized by solvothermal method. • Cd-MOF sensors can achieve the quantitative detection of His, NB, TC, and PTH with high sensitivity and selectivity. • Cd-MOF can achieve fast response and recycling when used as fluorescence sensor. • Cd-MOF can be applied to real samples when used as fluorescence sensor. • The possible mechanism of Cd-MOF in the detection process was discussed. A novel metal–organic framework (MOF) with the formula of [Cd(CIA)(4,4′-BB)·H 2 O]·H 2 O (Cd-MOF) (H 2 CIA = 5-methoxyisophthalic acid, 4,4′-BB: 4,4′-bis((1 H -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 Cd-MOF is μ 2 - к 1: к 0: к 2. 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 µM (His), 0.05 µM (NB), 0.2 µM (TC) and 0.01 µM (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. [ABSTRACT FROM AUTHOR]