Construction of naphthalimide-based fluorescent probe for sequential detection of Al³⁺ and NOR and its application in tea and honey

Metal aluminum ions and the antibiotic NOR have both benefited humanity and due to improper use, posed significant threats to the environment and human health. Although the correct and rational use of these substances is crucial, developing real-time, rapid, and highly sensitive detection of trace aluminum ions and NOR in the environment and organisms is more important for early diagnosis of potential related diseases. After several decades of development, fluorescence analysis has become a mainstream research method due to its ability to meet these requirements. In this study, a novel fluorescent probe Z-DBHM was designed and synthesized using naphthalimide as matrix. The obtained probe Z-DBHM exhibits high selectivity and sensitivity towards Al³⁺, with a detection limit of 0.79 μM, and can achieve the detection of Al³⁺ in tea. More importantly, the probe Z-DBHM exhibits extremely low cytotoxicity, successfully achieving intracellular Al³⁺ sensing. To our delight, the obtained Z-DBHM-Al³⁺ showed ultra-sensitive response to norfloxacin with the LOD 7.89 nM and successfully applied in honey detection. Finally, the integration of Z-DBHM's fluorescence color changes with a smartphone-assisted RGB color value application provides an effective strategy for detecting Al³⁺ and NOR.