Development of a Series of Near-Infrared Dark Quenchers Based on Si-rhodamines and Their Application to Fluorescent Probes
Development of a Series of Near-Infrared Dark Quenchers Based on Si-rhodamines and Their Application to Fluorescent Probes
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DOI：
10.1021/jacs.5b00246
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发表时间：
2015-04-15
影响因子：
15
通讯作者：
Urano, Yasuteru
中科院分区：
文献类型：
--
作者：
Myochin, Takuya;Hanaoka, Kenjiro;Urano, Yasuteru
基于Forster共振能量转移（FRET）机制的近红外（NIR）荧光探针具有各种实际优点，并且它们的分子设计通常基于使用NIR暗猝灭剂（其为非荧光染料）作为可裂解的FRET受体。然而，很少有NIR暗猝灭剂可以猝灭Cy 7区域（超过780 nm）中的荧光。在这里，我们描述了Si-罗丹明为基础的近红外暗淬灭剂（SiNQs），它显示了广泛的吸收覆盖这一地区。它们是非荧光的溶剂极性和pH值的独立性，可能是由于自由旋转的N原子和氧杂蒽部分之间的键。SiNQs可以很容易地进行结构修饰以调节其水溶性和吸收光谱，从而能够灵活地设计用于各种NIR荧光染料的适当FRET对。为了证明SiNQs的有用性，我们使用SiNQ 780设计并合成了用于基质金属蛋白酶（MMP）活性的近红外荧光探针。该探针1可以在体外、培养细胞和荷瘤小鼠中检测MMP活性，其中通过NIR荧光清楚地观察到肿瘤。我们相信SiNQs将有助于开发各种实用的近红外荧光探针。
Near-infrared (NIR) fluorescent probes based on the Forster resonance energy transfer (FRET) mechanism have various practical advantages, and their molecular design is generally based on the use of NIR dark quenchers, which are nonfluorescent dyes, as cleavable FRET acceptors. However, few NIR dark quenchers can quench fluorescence in the Cy7 region (over 780 nm). Here, we describe Si-rhodamine-based NIR dark quenchers (SiNQs), which show broad absorption covering this region. They are nonfluorescent independently of solvent polarity and pH, probably due to free rotation of the bond between the N atom and the xanthene moiety. SiNQs can easily be structurally modified to tune their water-solubility and absorption spectra, enabling flexible design of appropriate FRET pair for various NIR fluorescent dyes. To demonstrate the usefulness of SiNQs, we designed and synthesized a NIR fluorescent probe for matrix metalloproteinase (MMP) activity using SiNQ780. This probe 1 could detect MMP activity in vitro, in cultured cells and in a tumor-bearing mouse, in which the tumor was clearly visualized, by NIR fluorescence. We believe SiNQs will be useful for the development of a wide range of practical NIR fluorescent probes.