Hemicyanine-based High Resolution Ratiometric near-Infrared Fluorescent Probe for Monitoring pH Changes in Vivo
Hemicyanine-based High Resolution Ratiometric near-Infrared Fluorescent Probe for Monitoring pH Changes in Vivo
复制标题
基于半花青的高分辨率比率近红外荧光探针，用于监测体内 pH 值变化
DOI：
10.1021/ac5045498
复制
发表时间：
2015-02-17
影响因子：
7.4
通讯作者：
Yang, Ronghua
中科院分区：
文献类型：
--
作者：
Li, Yinhui;Wang, Yijun;Yang, Ronghua
细胞内pH是与细胞行为和病理状态相关的重要参数。通过高分辨率的近红外（NIR）荧光成像定量传感生物体系中的pH并监测其变化是必不可少的，但由于缺乏有效的探针而具有挑战性。为了实现良好的适应性，在这项研究中，一类分辨率可调的比率近红外荧光探针，具有稳定的近红外半花菁骨架承载不同的取代基，合理的设计和合成，使检测通过非侵入性光学成像的生物。基于羟基的质子化/去质子化，一个显着的近红外发射位移提供了响应于pH值的比例信号。同时，两个状态表现出良好的光稳定性，灵敏度和可逆性，有利于长期监测持久的pH值变化，而不干扰其他生物活性物种。其中，苯并噻唑类吸电子取代基修饰的近红外-Ratio-BTZ在pH环境由酸性变为碱性时，其荧光发射峰从672 nm变为748 nm，最大发射峰位移约76 nm，有望用于活细胞、组织和生物体的高分辨率pH成像。此外，NIR-比率-BTZ具有理想的pK（a）值（pK（a）约为7.2），用于监测接近中性的生理pH的微小波动。比率荧光测量有利于保证定量测量pH变化的准确性，以及实时监测活细胞和活小鼠中与pH相关的生理效应。结果表明，NIR-比率-BTZ是一种高灵敏度的比率式pH探针在体内，使其具有潜在的生物应用。
Intracellular pH is an important parameter associated with cellular behaviors and pathological conditions. Quantitative sensing pH and monitoring its changes by near-infrared (NIR) fluorescence imaging with high resolution in living systems are essential but challenging due to the lack of effective probes. To achieve good adaptability, in this study, a class of resolution-tunable ratiometric NIR fluorescent probes, which possess a stable NIR hemicyanine skeleton bearing different substituents, are rationally designed and synthesized, enabling detection through noninvasive optical imaging of organisms. Based on the protonation/deprotonation of the hydroxy group, a marked NIR emission shift provides a ratio signal in response to pH. Meanwhile, two states exhibit good photostability, sensitivity and reversibility, conducive to longtime monitoring of persistent pH changes without disturbance of other biological active species. Among the series, NIR-Ratio-BTZ modified with an electron-withdrawing substituent of benzothiazole exhibited the largest emission shift of about 76 nm from 672 to 748 nm with the pH environment changing from acidic to basic, which could be considered as a good candidate for high resolution pH imaging in live cells, tissues and organisms. Moreover, NIR-Ratio-BTZ has an ideal pK(a) value (pK(a) approximate to 7.2) for monitoring the minor fluctuations of physiological pH near neutrality. The ratiometric fluorescence measurement is beneficial to ensure the accuracy of quantitative measuring pH changes, as well as the real-time monitoring pH-related physiological effects both in living cells and living mice. The results demonstrate that NIR-Ratio-BTZ is a highly sensitive ratiometric pH probe in vivo, giving it potential for biological applications.