Multifunctional Cadmium-Based Metal–Organic Frameworks for the Detection of Ion and Molecule in Aqueous Media

The development of materials capable of simultaneously detecting multiple analytes has been a significant challenge. This paper presents the synthesis of two novel Cd-MOFs, namely CUST-781 and CUST-782 (CUST = Changchun University of Science and Technology), using a solvothermal synthesis method. CUST-781 and CUST-782 were carefully characterized. CUST-781 and CUST-782 are both two-dimensional supramolecular structures formed through hydrogen bonding. Luminescence sensing studies demonstrate that CUST-781 can sensitively detect lower concentrations of Fe3+, 2,4,6-trinitrophenol (TNP), and the antibiotic ceftriaxone sodium. Similarly, CUST-782 shows fluorescence quenching in response to Fe3+, Cr2O72–, TNP, and the antibiotic tetracycline. The possible mechanisms of fluorescence quenching were investigated in detail. It can be inferred that CUST-781 and CUST-782 serve as fluorescent probes to provide a new strategy for directly detecting harmful substances in aqueous solution.