Construction of a novel magnetic metal-organic framework fluorescent sensor for selective detection and magnetic separation of 4-Nitrophenol

Abstract

The development of a sensitive and selective fluorescent sensor for 4-Nitrophenol (4-NP) is very important for ensuring the environmental and ecological security. Herein, a novel fluorescent sensor using magnetic metal-organic framework (Fe3O4@SiO2@MOF) has been constructed specifically for detecting and magnetic separating 4-NP in real water samples. The synthesized Fe3O4@SiO2@MOF were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Thermo-gravimetric analysis (TG), X-ray diffraction spectroscopy (XRD), Magnetic saturation intensity measurement and N2 adsorption-desorption analysis. The prepared Fe3O4@SiO2@MOF presented core-shell structure and good thermal-stability. Under optimum conditions, Fe3O4@SiO2@MOF exhibits rapid response of detecting 4-NP within 30 s, satisfactory selectivity and magnetic properties, outstanding reusability and excellent stability. Furthermore, a wide linear range of 5.0-200 μM with a detection limit of 2.2 μM was attained. In addition, real water samples were successfully analyzed with Fe3O4@SiO2@MOF. The spiked recoveries and the relative standard deviation were 92.2 %-104.8 % and 1.2 %-3.3 %, respectively. Overall, this strategy provides new sights into the construction of practical fluorescent sensors for sensitive and selective detection of 4-NP in environmental samples.