Tb-L对水中Fe³⁺的传感性能研究

Sensing Performance of Tb-L for Fe³⁺ in Aqueous Media

摘要: 铁在生命活动和环境中具有重要作用，但过量的Fe³⁺会对生态系统和人类健康造成严重危害。因此，发展高效、灵敏的Fe³⁺检测方法具有重要意义。本研究成功合成了一种稀土配合物Tb-L，并系统考察了其在水介质中对Fe³⁺的荧光传感性能。结果表明，Tb-L在298 nm激发下表现出明亮的绿色特征发射，对多种常见金属离子干扰具有良好的抗性，而Fe³⁺能够选择性地猝灭其发光，猝灭效率高达95.88%。滴定实验进一步揭示Tb-L在0~50 μM范围内对Fe³⁺具有良好的线性响应，检测限为724.8 nM，且响应时间短于15 s，并具备良好的可循环使用性。机理分析表明，能量竞争吸收与内滤效应的协同作用是猝灭的主要原因。本研究为稀土配合物在水环境中Fe³⁺的快速、灵敏检测提供了新的候选材料和研究思路。

Abstract: Iron plays a vital role in both biological systems and the environment; however, excessive Fe³⁺ can pose serious threats to ecosystems and human health. Therefore, the development of efficient and sensitive detection methods for Fe³⁺ is of great significance. In this work, a rare-earth complex, Tb-L, was successfully synthesized, and its fluorescence sensing performance toward Fe³⁺ in aqueous media was systematically investigated. The results demonstrate that Tb-L exhibits bright green characteristic emission under 298 nm excitation and shows excellent resistance to interference from various common metal ions, while Fe³⁺ selectively quenches its fluorescence with a quenching efficiency of up to 95.88%. Titration experiments further revealed a good linear response of Tb-L to Fe³⁺ in the concentration range of 0~50 μM, with a detection limit of 724.8 nM, a rapid response time of less than 15 s, and favorable recyclability. Mechanistic studies indicate that the synergistic effect of competitive absorption and the inner filter effect is primarily responsible for the fluorescence quenching. This work highlights Tb-L as a promising candidate for the rapid and sensitive detection of Fe³⁺ in aqueous environments and provides new insights for the design of rare-earth-based chemosensors.