苯乙烯类菁染料pH探针的合成与活细胞成像

Synthesis of pH Probe Based on Styrylcyanine Dyes and Fluorescence Image in Live Cell

合成了一个以苯乙烯类菁染料为母体的含胺类基团的pH荧光探针,合成方法简单,产物收率高,提纯方便.在乙醇-水体系中的性能测试结果表明,随着pH值的降低,其非质子化形态的吸收峰强度逐渐降低,而质子化形式的长波长吸收峰强度逐渐升高,长、短波长相差(Δλ)130 nm,颜色由黄色变成粉红色,利于可视观察;探针在氨基呈非质子化形式时没有荧光,氨基质子化后探针的荧光强度显著增强.活细胞实验表明,探针可以穿透细胞膜,在细胞质内pH值偏低区域显示红色荧光,可以用来定性探测酸性细胞器.

Fluorescent pH indicators have been widely applied in recent years to monitor changes in intracellular pH.Though some pH probes were synthesized and applied to sense the acidic organelles in live cells.However,the syntheses of these probes were very complicated.So,one pH fluorescence probe based on amino-styrylcyanine was synthesized with good yield and its purification was easy.Its abilities as pH probe were tested in ethanol-water solution.The results showed the absorption intensity of the base form（short-wavelength） decreased with the decreasing of pH,at the same time,the absorption intensity of the protonated forms（long-wavelength） increased.The color of the solution changed from yellow to pink.The base form had no fluorescence,but the fluorescence intensity of the protonated form increased remarkably.The pKa of the probe was about 4.97.Live cell fluorescence images indicated the probe possesses good cell membrane permeation and can associate with lower pH yield inside the cytosol which can be applied to sense acidic organelles in live cells.