Heteronuclear metal-organic framework-based fluorescent sensor for the detection of tetracycline antibiotics

The residues of tetracycline antibiotics (TCs) have caused serious environmental pollution due to the multi-field application. In order to rapidly detect TCs, there is an urgent need to design new fluorescence sensor. Herein, a heterometallic metal-organic framework (HNU-61) is constructed and used as a fluorescence sensor for detecting the TCs. In HNU-61, both Zn2+ and Li+ ions are assembled into the crystal structure, in which Zn2+ adopts tetrahedral coordination mode, and can be served as the potential coordination site. The 3D structure of HNU-61 is formed by the connection between Zn2+/Li+ and isophthalic acid (m-BDC2-) ligand with the 1D channel along a axis. Among the six categories of antibiotics, HNU-61 can effectively detect TCs, including tetracycline hydrochloride (TCY), chlortetracycline hydrochloride (CTE), doxycycline hydrochloride (DOX), and oxytetracycline hydrochloride (OXY) with the detection limits of 6.5 x 10(-8) M, 9.2 x 10(-8) M, 4.5 x 10(-7) M, and 3.9 x 10(-7) M, respectively. Furthermore, HNU-61 enables a rapid and sensitive detection of TCs with good anti-interference and circulation. The detection mechanism can be attributed to the interaction between Zn2+ in HNU-61 and TCs.