Fluorescence sensor array for determination of multiple metal ions in water samples utilizing MOF-808@ZIF-8 and CDs@ZIF-8 composite nanomaterials.

To metal-organic frameworks (MOFs) composite materials with excellent luminescent properties, MOF-808@ZIF-8 and CDs@ZIF-8, were utilized to design a fluorescence sensor array. The sensor array was applied to the detection of ten heavy metal ions (Ag+, Ba2+, Cd2+, CrO42−, Cu2+, Fe3+, Fe2+ and Ni2+, Pb2+, Zn2+) in water. The interactions between the heavy metals and the MOF-based composites, as well as inner filter effect (IEF) mediated mechanisms, enables these ions to selectively alter the luminescent properties of MOF-808@ZIF-8 and CDs@ZIF-8, producing unique fluorescence signatures, facilitating precise identification. In particular, it enables the quantitative detection of Fe2+, Fe3+, and CrO42−, with detection limits reaching 241, 84 and 178 nM, respectively. These unique optical responses are subsequently analyzed and classified using pattern recognition algorithms. Significantly, the proposed strategy has been successfully applied to the detection of heavy metals in real water samples. This study proposes a rapid analytical method for identifying heavy metals in water, which has a promising application prospect in real-time monitoring of various pollutants in the water environment.