Rapid and accurate detection of early cancer biomarkers not only provides a scientific tool for cancer diagnosis, but also helps prevent further cancer progression. Herein, a mitochondrial-targeted two-photon fluorogenic probe (CQ-1) is designed to visualize the changes of nitroreductase (NTR) and viscosity in mitochondria of cancer cells. The CQ-1 consists of the N, N-dimethylnaphthalen-2-amine, pyridine salt and p-nitrobenzene. It shows the significant fluorescence enhancement of CQ-1 with the increase of viscosity due to the limited intramolecular rotation, and turn-on fluorescence signal after CQ-1 reacted with NTR since intramolecular charge transfer generation. Meanwhile, CQ-1 displays fascinating mitochondrial targeting ability. Due to the satisfactory detection capability of CQ-1, we further apply CQ-1 to monitor variations of mitochondrial viscosity and NTR in cancer cells by two-photon fluorescent microscope, as well as for specific imaging of NTR in zebrafish. We expect that this dual-response fluorogenic probe will provide a convenient and effective chemical tool for understanding the physiological functions of NTR and viscosity as well as for the diagnosis of important markers associated with cancer.

快速准确地检测早期癌症生物标志物不仅为癌症诊断提供了科学工具，而且有助于防止癌症进一步进展。在此，一种靶向线粒体的双光子荧光探针 ( CQ-1 ) 旨在可视化癌细胞线粒体中硝基还原酶 (NTR) 和粘度的变化。CQ-1由N , N-二甲基萘-2-胺、吡啶盐和对硝基苯组成。它表明由于分子内旋转受限， CQ-1的荧光随粘度的增加而显着增强，并且在CQ-1后开启荧光信号由于分子内电荷转移产生，与 NTR 反应。同时，CQ-1显示出迷人的线粒体靶向能力。由于CQ-1具有令人满意的检测能力，我们进一步应用CQ-1通过双光子荧光显微镜监测癌细胞线粒体粘度和NTR的变化，以及斑马鱼NTR的特异性成像。我们希望这种双响应荧光探针将为了解 NTR 和粘度的生理功能以及诊断与癌症相关的重要标志物提供方便有效的化学工具。