An optical ESIPT sensor for Hg²⁺ and cysteine based on a naphthalene platform (1) was designed and synthesized by a one step reaction and characterized by using common spectroscopic techniques. Upon addition of Hg²⁺ to a 9 : 1 (v/v) aqueous CH₃CN (pH 7.0 HEPES buffer) solution of 1, the highly fluorescent probe becomes weakly fluorescent, showing a color change from colorless to dark yellow visible to the naked eye and from fluorescent blue to light yellow when irradiated with 365 nm light. The sensing mechanism has been supported by DFT and ¹H NMR titration studies. The in situ generated 1–Hg²⁺ complex has been used for effectively sensing Cys. Owing to the stronger binding affinity of the sulfhydryl group to Hg²⁺, Cys can extract Hg²⁺ from the 1–Hg²⁺ complex, resulting in the release of 1 and revival of the emission intensity. Sensor 1 has also been successfully applied for the detection of Hg²⁺ in real water samples with good recovery. The alternate addition of Hg²⁺ and Cys ions generated “on–off–on” fluorescence cycles, which enabled 1 to be used as a reversible and reconfigurable set/reset memorized device at the molecular level.

中文翻译：

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使用基于萘的ESIPT传感器 级联识别Hg ²⁺和半胱氨酸及其在设置/重置存储设备中的应用†

通过一步反应设计合成了基于萘平台（1）的Hg ²⁺和半胱氨酸的光学ESIPT传感器，并通过常规光谱技术对其进行了表征。一旦加入汞²⁺至9：1（V / V）含水CH ₃ CN（pH为7.0的HEPES缓冲液）的溶液1中，高荧光探针变弱荧光，显示从无色到暗黄色可见的颜色变化肉眼观察，并在365 nm的光照射下从荧光蓝色变为浅黄色。DFT和¹ H NMR滴定研究支持了该传感机制。该原位生成的1 -Hg ²⁺复合物已被用于有效地感测Cys。由于巯基对Hg ²⁺具有更强的结合亲和力，Cys可以从1 –Hg ²⁺络合物中提取Hg ²⁺，从而释放1并恢复发射强度。传感器1也已成功应用于具有良好回收率的真实水样中Hg ²⁺的检测。Hg ²⁺和Cys离子的交替添加产生“开-关-开”的荧光循环，这使1可以在分子水平上用作可逆和可重构的设置/重置存储装置。