He Liangyu, Li Qi, Zhang Yaqing, Huang Kun, Du Bingxin, Liang Lijuan
School of Chemistry and Chemical Engineering, Science Park, China West Normal University, Nanchong 637002, China.
School of Chemistry and Chemical Engineering, Science Park, China West Normal University, Nanchong 637002, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Aug 5;296:122672. doi: 10.1016/j.saa.2023.122672. Epub 2023 Mar 28.
The pollution caused by mercury ions (Hg) poses a potential threat to public health. Therefore, monitoring Hg concentration in the environment is necessary and significant. In this work, a naphthalimide functionalized fluoran dye NAF has been prepared, which shows a new red-shift in emission at 550 nm with the maximum intensity in a mixture of water-CHCN (v/v = 7/3) due to aggregating induced emission (AIE) effect. Meanwhile, NAF can be employed as a Hg ions sensor, which displays a selective and sensitive response to Hg ions by the reduced fluorescence of naphthalimide fluorophore and increased fluorescence of fluoran group, respectively, showing ratiometric fluorescence signal changes with more than 65-fold emission intensity ratio increase and naked eyes visible color change. In addition, the response time is fast (within 1 min) and the sensing can be conducted in a wide pH range (4.0-9.0). Moreover, the detection limit has been evaluated to be 5.5 nM. The sensing mechanism may be attributed to the formation of a π-extended conjugated system due to the Hg ions-induced conversion of spironolactone to the ring-opened form, partially accompanied by the fluorescence resonance energy transfer (FRET) process. Significantly, NAF exhibits suitable cytotoxicity to living HeLa cells, which allows it to be utilized for ratiometric imaging of Hg ions assisted by confocal fluorescence imaging.
汞离子（Hg）造成的污染对公众健康构成潜在威胁。因此，监测环境中的汞浓度是必要且重要的。在这项工作中，制备了一种萘二甲酰亚胺功能化的荧烷染料NAF，由于聚集诱导发光（AIE）效应，它在水 - 乙腈（v/v = 7/3）混合溶液中于550 nm处发射出现新的红移，且强度最大。同时，NAF可作为汞离子传感器，分别通过萘二甲酰亚胺荧光团荧光降低和荧烷基团荧光增强对汞离子表现出选择性和灵敏的响应，呈现出比率荧光信号变化，发射强度比增加超过65倍且肉眼可见颜色变化。此外，响应时间快（在1分钟内），传感可在较宽的pH范围（4.0 - 9.0）内进行。而且，检测限经评估为5.5 nM。传感机制可能归因于汞离子诱导螺内酯转化为开环形式从而形成π - 扩展共轭体系，部分伴随着荧光共振能量转移（FRET）过程。值得注意的是，NAF对活的HeLa细胞表现出合适的细胞毒性，这使其能够用于共聚焦荧光成像辅助的汞离子比率成像。
