基于吲哚半花菁结构的比值式pH荧光探针

Ratiometric pH fluorescent probe based on indole hemi-cyanine derivative

设计合成了一种基于半花菁类结构的比值式pH荧光探针，能快速响应pH值的变化，对常见金属离子具有较好的抗干扰能力。在pH 5.4～7.2范围内，随着pH值升高，探针紫外可见吸收光谱最大吸收波长由422 nm红移至525 nm。激发波长为430 nm时，荧光发射峰峰高之比（ I513 nm/I553 nm ）与pH值的变化有良好的线性关系，可用于检测生物体内pH的变化。HeLa细胞毒性试验表明，该探针具有较低的细胞毒性。

A new hemi-cyanine based ratiometric fluorescent pH probe was synthesized. The probe re-sponds to pH with high selectivity and sensitivity. A red-shift of UV-Vis absorption occurred from 422 nm to 525 nm with the increase of pH from 5 to 9 . The fluorescence intensity ratio（ R=I513 nm/I553 nm ）exhib-its a good linearity with pH within the range of 5. 4～7. 2 at λex =430 nm. MTT assay revealed that the probe has low cytotoxicity.