The Effect of Amine-Functional Group on Heavy Metal Ion Detection of a Cu-Based Metal-Organic Framework

Owing to their enriched host-guest chemistry and high porosity, metalorganic frameworks (MOFs) have been applied extensively in the detection of a large variety of hazardous chemicals, especially metal ions, using different instrumental methods, such as photoluminescence. In this study, two pillarlayered MOFs, [Cu2(BDC)2(DABCO)] and its amine-functionalized isostructure [Cu2(NH2-BDC)2(DABCO)], were successfully prepared to underscore the role of amino group in sensing metal ions via utilizing the photoluminescencebased method. These materials could recognize copper(II) cations efficiently by changing the luminescent response in less than 20 minutes. By increasing the concentration of Cu(II) solution, first, the luminescent response changes occurred intensely, then equilibrium was reached and no more changes were observed. In the presence of other metal cations, the sensors recognized the analyte almost selectively. At the end of the experimental tests, a reasonable mechanism of sensing was proposed using FTIR spectroscopy and PXRD patterns. They confirmed that the introduction of the analyte did not collapse the structure; therefore, only the chemical interactions between the walls of pores and Cu(II) ions were responsible for the purposed application.