Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, China.
Technical Institute of Physics & Chemistry, Key Laboratory of Photochemical Conversion & Optoelectronic Materials, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, China.
Nat Commun. 2018 Jan 24;9(1):362. doi: 10.1038/s41467-017-02270-0.
Chromophore reactions with changes to conjugation degree, especially those between the conjugated and unconjugated state, will bring a large spectral variation. To realize such a process, a meso-naked BODIPY (MNBOD) with two electron-withdrawing groups around the core is designed and synthesized. The resulting system is extremely sensitive to bases. The red, highly fluorescent solution readily becomes colorless and non-fluorescent after base addition; however, the color and fluorescence can be totally and instantly restored by addition of acid or formaldehyde. Analyses show that two identical MNBODs are connected by a C-C single bond (sp) at the meso-position through a radical reaction that results in an unconjugated, colorless dimer complexed with bases. When the bases are consumed, the dimer immediately dissociates into the red, highly fluorescent, conjugated MNBOD monomer. With 260 nm spectral change and over 120,000 turn-on ratio, this chromophore-reaction can be utilized as a sensitive reaction-based dual-signal probe.
发色团反应伴随着共轭程度的变化，特别是在共轭态和非共轭态之间的变化，会带来很大的光谱变化。为了实现这样的过程，设计并合成了一个带有两个吸电子基团的间位裸露 BODIPY（MNBOD）。所得体系对碱基极其敏感。红色、高荧光溶液在加入碱基后很容易变成无色和非荧光的；然而，通过加入酸或甲醛，颜色和荧光可以完全和瞬间恢复。分析表明，两个相同的 MNBOD 分子通过自由基反应在间位以 C-C 单键（sp）连接，形成与碱基配位的无色、非共轭二聚体。当碱基被消耗时，二聚体立即解离成红色、高荧光、共轭的 MNBOD 单体。该发色团反应具有 260nm 的光谱变化和超过 120,000 的开启比值，可用作灵敏的基于反应的双信号探针。
