A new type of Eu(III)-gatifloxacin complex with characteristic red luminescence has been prepared. Due to the presence of ionization effect linked to the organic chromophore , the molecular fluorescent sensor demonstrated variable pH-sensitive absorption and emission curves. The red emission derived from europium ions was strong during pH range 8–10. Between pH = 7 and 4, the europium emission remained relatively stable and fluorescence signals of gatifloxacin has been improved substantially. Under acidic conditions (pH = 1 to 3), the dramatic changes in the emission colors (from red, yellow to green) were clearly observed. Moreover, the excitation wavelength can be extended into the visible light range (Ex = 411 nm) by using the concentration effect experiment. Importantly, it gave turn- off emissions in the presence of Cu 2+ or Fe 3+ and the detection limits were determined to be 6.5 μM for Cu 2+ and 6.2 μM for Fe 3+ respectively.
Kai Wang,Peiwen Lv,Mingyang Liu,Yunjun Mei,Yifan Zhang,Yuqiu Zheng,Jintao Guan
Traditional fluorescent probes have challenges, including aggregation-induced quenching, biological incompatibility, and suboptimal selectivity. In this study, we developed a novel probe derived from natural rutin featuring an aggregation-induced emission (AIE) effect. Through hydroxy engineering of rutin, the optimized probe enables precise detection of Fe 3+ via 2:1 stoichiometric coordination. The probe demonstrates remarkable analytical performance, with a detection limit as low as 0.22 μM. Concentration-dependent responses were observed within 0–20 μM, with significant linearity ( R 2 > 0.99) in the 0–10 μM range. Density functional theory calculations reveal that the binding of Fe 3+ effectively suppresses intramolecular charge transfer. The hydroxy-engineered modification plays a pivotal role in facilitating complexation for bond formation and providing appropriate steric hindrance. This research establishes a new benchmark for natural product-based AIE probes and deepens understanding of the structure–activity relationships governing flavonoid-metal recognition.
危险品化学品经营许可证（带存储）