In this work, promising novel ferrous metal-organic framework nanoparticles (Fe(II)-MOF-NPs) were prepared via a simple method. The produced materials were fully characterized using FE-SEM, EDX, HR-TEM, elemental analysis, mass spectrometry, FT-IR, UV-Vis, TG/DSC, XRD, XPS, and analysis of magnetic properties. Colorimetric and photoluminescence (PL) investigations of Fe(II)-MOF-NPs were also carried out. The specific coordination binding between the Hg(II) and amino groups of the MOF led to an enhancement of the PL and the absorbance intensities. Therefore, Hg(II) concentrations could be determined quantitatively. A fast, sensitive, and selective method of mercury ion detection based on colorimetric and PL chemosensors using Fe(II)-MOF-NPs was developed. At optimal conditions, the PL and colorimetric chemosensors exhibited stable responses for Hg(II) in a concentration range of 1.0 nM to 1.0 μM with detection limits (LOD) = 1.17 and 1.14 nM and quantification limits (LOQ) = 1.59 and 1.48 nM, respectively. The developed PL and colorimetric chemosensors exhibited high selectivity towards Hg(II) over the other competing metal ions. Moreover, both ultrasensitive chemosensors were further investigated for determination of Hg(II) in different water sources (tap, mineral, river, sea, and wastewater) as well as in biological samples (blood serum and urine samples), with satisfactory recoveries. Graphical abstract.
Keywords: Chemosensor; Colorimetric; Ferrous metal–organic framework; Mercury; Nanoparticles; Photoluminescence.