文献类型：期刊文献

英文题名：Novel cyanine dyes as fluorescent pH sensors: PET, ICT mechanism or resonance effect?

作者：Xu, Yufang[1]; Liu, Yan[1]; Qian, Xuhong[1]

机构：[1]E China Univ Sci & Technol, Sch Pharm, Shanghai Key Lab Chem Biol, Shanghai 200237, Peoples R China

年份：2007

卷号：190

期号：1

起止页码：1

外文期刊名：JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

收录：;EI(收录号：20242616536780);WOS:【SCI-EXPANDED(收录号:WOS:000247857900001)】；

语种：英文

外文关键词：cyanine dyes; fluorescent pH sensors; PET mechanism; ICT mechanism; resonance effect

摘要：Cyanine and related polymethine dyes have been widely used as fluorescent and phosphorescent dyes for biological investigations. But the mechanism of this kind of cyanine dye as pH sensor is still not clear. In this paper, two groups of cyanine dyes were designed and synthesized, each including two asymmetry cyanine dyes and one symmetry dye. The UV-vis and fluorescent spectra of compounds Ia-b and IIa-b were recorded in phosphate buffers with different pH value. It was found that these compounds could be used as a kind of pH sensors with high pK(a) value. The calculation on structures or conformations of compounds Ia-b, IIa-b and Ic before and after protonation revealed that the planar conjugations were different between non-protonic and protonic forms. It implied that the change from PET to ICT system was possible in the process of binding between polymethine cyanine dyes and proton. (c) 2007 Elsevier B.V. All rights reserved.