针对目前广泛采用的二-（2-吡啶基）胺（DPA）作为Zn²⁺识别基团的各类荧光探针背景荧光普遍偏高的问题，我们提出基于荧光素开闭环和猝灭基团双猝灭机制的OFF-ON型Zn²⁺检测策略，从而提高Zn²⁺荧光探针的灵敏度。本文合成一种含有荧光素前体分子、DPA为识别基团、二甲氨基偶氮苯甲酸（DABCYL）为猝灭基团的锌离子荧光探针（FL-ZJ），通过荧光光谱研究了其与锌离子的荧光响应。研究结果表明，FL-ZJ在526 nm处表现出较低的荧光活性，但是当体系中有锌离子存在时，FL-ZJ在526 nm处的荧光强度增强至原来的约17.4倍，相应的体系颜色由无色变为黄色，其他金属离子的加入不影响FL-ZJ的荧光强度，说明FL-ZJ能够高效灵敏的检测Zn²⁺，其对Zn²⁺的检出限仅为14.6 nmol/L。进一步通过Job's Plot实验及高效液相色谱推测出该探针检测锌离子的机理为：锌离子的配位诱导了荧光素的开环及猝灭基团的分子内消除反应，进而实现了探针对Zn²⁺的专一性检测。

To enhance the sensitivity of fluorescence probes for the detection of Zn²⁺, this study introduces an OFF-ON Zn²⁺ detection strategy. This approach utilizes a dual quenching mechanism involving fluorescein ring closure-opening and (E)-4-((4-(dimethylamino) phenyl) diazenyl) benzoic acid (DABCYL) as a dual quencher. The primary objective is to address the issue of high background fluorescence associated with bis (pyridin-2-ylmethyl) amine (DPA) based Zn²⁺ recognition groups in various fluorescence probes. The Zn²⁺ fluorescence probe 4',5'-bis((bis(pyridin-2-ylmethyl)amino)methyl)-2', 7'-dichloro-3'-hydroxy-3-oxo-3H-spiro [isobenzofuran-1,9'-xanthen]-6'-yl (E)-4-((4-(dimethylamino) phenyl) diazenyl) benzoate (FL-ZJ) was synthesized using a fluorescein precursor molecule, with DPA serving as the recognition group and DABCYL functioning as the dual quencher. The fluorescence response of FL-ZJ to Zn²⁺ was investigated through fluorescence spectroscopy. Results indicated that FL-ZJ exhibited minimal fluorescence activity at 526 nm in the absence of Zn²⁺. Upon introduction of Zn²⁺, the fluorescence intensity at 526 nm increased to approximately 17.4-fold, accompanied by a color change from colorless to yellow. The detection limit for Zn²⁺ using this probe was determined to be 14.6 nmol/L. Further analysis via Job's Plot experiments and high-performance liquid chromatography revealed that coordination-induced ring opening of the fluorescein moiety and intramolecular elimination of the quenching group facilitated the selective detection of Zn²⁺.