Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Org Chem. 2013 Jun 21;78(12):6121-30. doi: 10.1021/jo400783x. Epub 2013 Jun 7.
A series of deep red fluorescent dyes (CR1 to CR3) was developed via introduction of a coumarin moiety into the rhodamine molecular skeleton. The novel dyes possessed the individual advantages of coumarin and rhodamine derivatives, and the emission wavelength was extended to the deep red region (>650 nm) due to the extension of fused-ring conjugate structure simultaneously. To illustrate its value, we designed and conveniently synthesized a series of novel deep red bioimaging dyes (CR1E to CR3E) by esterification of CR1 to CR3, which could selectively stain mitochondria. They were superior to the MitoTrackers for mitochondrial staining in terms of large Stokes shift, excellent contrast for imaging, high photostability, and low cytotoxicity. Furthermore, the fluorescence of the coumarin moiety and rhodamine-like fluorophore could be switched like classical rhodamine. Thus, they could be used as an effective platform in constructing fluorescence sensors. Based on this fact, we constructed a novel ratiometric sensor (CR1S) for Hg(2+) with good selectivity that could be successfully applied to the imaging of Hg(2+) in living A549 cells. This design strategy is straightforward and adaptable to various deep red dyes and sensing platforms by simply introducing different fluorophores.
一系列深红光荧光染料（CR1 至 CR3）是通过在罗丹明分子骨架中引入香豆素部分而开发的。这些新型染料具有香豆素和罗丹明衍生物的各自优点，并且由于稠合环共轭结构的同时延伸，发射波长延伸到深红光区域（>650nm）。为了说明其价值，我们通过 CR1 至 CR3 的酯化设计并方便地合成了一系列新型深红光生物成像染料（CR1E 至 CR3E），它们可以选择性地染色线粒体。与线粒体染色的 MitoTrackers 相比，它们在斯托克斯位移大、成像对比度好、光稳定性高、细胞毒性低等方面具有优势。此外，香豆素部分和类似罗丹明的荧光团的荧光可以像经典罗丹明一样切换。因此，它们可以用作构建荧光传感器的有效平台。基于这一事实，我们构建了一种用于 Hg(2+) 的新型比率传感器（CR1S），具有良好的选择性，可以成功应用于活 A549 细胞中 Hg(2+)的成像。这种设计策略简单直接，通过简单引入不同的荧光团，适用于各种深红光染料和传感平台。
