Six coumarin-based fluorescent probes were designed and synthesized for the detection of sulfite. The probes were constructed based on “fluorophore-receptor/linker-steric group” mode with N,N-diethyl-7-aminocoumarin (DEA) or 2,3,5,6-1H,4H-tetrahydro-quinolazino-(9,9a,1-gh)coumarin (THQ) as the fluorophore, 2-naphthyl ketone (N) or phenyl ketone (B) as the steric group and vinyl (1) or 1,3-butadienyl (2) as the receptor/linker. The effects of the fluorophore, the linker and the steric group on the photophysical properties and sensing performance were systematically studied. Among all the probes, DEA-N2 exhibited the most excellent spectral responses toward sulfite: upon addition of sulfite, the absorption and emission maxima shifted from 488 nm to 405 nm and–from 684 nm to 484 nm, respectively. I/I displayed good linear relationship with sulfite concentration in the range of 3–50 μM, with a detection limit of 0.31 μM. The experimental results demonstrate that DEA-N2 has potential in ratiometric fluorescent imaging of mitochondrial sulfite in living cells.

中文翻译：

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用于亚硫酸盐比色和比率荧光检测的香豆素荧光探针：结构-活性关系


设计并合成了六种基于香豆素的荧光探针用于检测亚硫酸盐。探针基于“荧光团-受体/连接体-空间基团”模式构建，使用N,N-二乙基-7-氨基香豆素（DEA）或2,3,5,6-1H,4H-四氢喹嗪基-(9, 9a,1-gh)香豆素 (THQ) 作为荧光团，2-萘基酮 (N) 或苯基酮 (B) 作为空间基团，乙烯基 (1) 或 1,3-丁二烯基 (2) 作为受体/连接体。系统研究了荧光团、连接体和空间基团对光物理性质和传感性能的影响。在所有探针中，DEA-N2 对亚硫酸盐表现出最优异的光谱响应：添加亚硫酸盐后，吸收和发射最大值分别从 488 nm 移至 405 nm 和从 684 nm 移至 484 nm。 I/I 与亚硫酸盐浓度在 3–50 μM 范围内表现出良好的线性关系，检测限为 0.31 μM。实验结果表明 DEA-N2 在活细胞中线粒体亚硫酸盐的比率荧光成像中具有潜力。