基于SDBS敏化的LFLX-Eu³⁺荧光探针对环境水样中总磷的检测研究

Study on SDBS-Sensitized LFLX-Eu³⁺ Fluorescent Probe for the Total Phosphorus Detection in Environmental Water Samples

摘要: 本工作构筑了一种基于十二烷基苯磺酸钠(SDBS)调控的左氧氟沙星(LFLX)-Eu³⁺配合物荧光探针，用于磷酸盐(Pi)的灵敏选择性检测。低浓度的SDBS通过诱导LFLX向Eu³⁺的能量转移，显著增强Eu³⁺特征荧光，同时淬灭LFLX荧光。由于Eu³⁺与Pi中氧原子的强配位作用，Pi的加入可阻碍LFLX向Eu³⁺的能量转移，导致Eu³⁺荧光淬灭，同时恢复LFLX荧光。该荧光探针可实现对0.1~25 μM Pi的分析检测，检出限为0.027 μM，且对Pi具有良好的特异性荧光响应。此外，Pi引起的探针荧光颜色变化可用于Pi的裸眼可视化分析。该荧光探针不仅为环境水样中总磷的分析测定提供了新方法，而且为构建基于能量转移机制的荧光探针提供了新思路。

Abstract: In this work, a fluorescent probe of levofloxacin (LFLX)-Eu³⁺ complex regulated by sodium dodecylbenzenesulfonate (SDBS) was developed for the sensitive and selective detection of phosphate (Pi). SDBS with low concentration significantly enhanced the characteristic fluorescence of Eu³⁺ and quenched the fluorescence of LFLX by promoting the energy transfer of LFLX to Eu³⁺. Since Eu³⁺ has stronger coordination with the oxygen-donor atoms of Pi, the addition of Pi can hinder the energy transfer of LFLX to Eu³⁺, resulting in the quenching of Eu3+ fluorescence and the recovery of LFLX fluorescence simultaneously. Based on the dual fluorescence signals, the fluorescent probe can achieve the detection of Pi in the range of 0.1~25 μM, and a detection limit of 0.027 μM was obtained. This probe exhibited a good specific fluorescence response to Pi. In addition, the fluorescence color change of the probe caused by Pi can be used for naked-eye visual analysis of Pi. This fluorescent probe not only provides a new method for the determination of total phosphorus in environmental water samples, but also provides a new strategy for the fabrication of fluorescent probes based on energy transfer mechanism.