College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, P. R. China.
Anal Chem. 2015 Apr 7;87(7):3678-84. doi: 10.1021/ac503975x. Epub 2015 Mar 11.
Mitochondrial reactive oxygen species (ROS) and pH fluctuations are closely correlated with mitochondrial dysfunctions, which are implicated in various human diseases including neurodegenerative disorders and cancers. Simultaneously monitoring the changes of ROS and pH of mitochondria remains a major challenge in the mitochondrial biology. In this study, we develop a novel mitochondria-targeted fluorescent nanosensor for real-time imaging of the fluctuations of hydrogen peroxide (H2O2) and pH in living cells. The fluorescence probes for detecting pH and H2O2 were loaded in the small-sized mesoporous silica nanoparticles (MSN). Then the polyethylenimine was attached to cap the pores of MSN, the triphenylphosphonium was further modified to target mitochondria in living cells. Confocal fluorescence imaging indicated that the nanosensor could effectively target mitochondria and successfully achieved real-time imaging of mitochondrial H2O2 and pH fluctuations in living cells. Notably, this is a single nanosensing system that is capable of visualizing multiple subcellular analytes at the same time and position by multicolor fluorescence imaging. The current approach can provide a promising tool to investigate the interplaying roles of various subcellular analytes in living cells.
线粒体活性氧（ROS）和 pH 值波动与线粒体功能障碍密切相关，线粒体功能障碍与多种人类疾病有关，包括神经退行性疾病和癌症。同时监测线粒体中 ROS 和 pH 值的变化仍然是线粒体生物学中的一个主要挑战。在这项研究中，我们开发了一种新型的线粒体靶向荧光纳米传感器，用于实时成像活细胞中过氧化氢（H2O2）和 pH 值的波动。用于检测 pH 值和 H2O2 的荧光探针被装载在小尺寸的介孔硅纳米颗粒（MSN）中。然后用聚乙烯亚胺覆盖 MSN 的孔，进一步用三苯基膦修饰以靶向活细胞中的线粒体。共聚焦荧光成像表明，该纳米传感器能够有效地靶向线粒体，并成功实现了活细胞中线粒体 H2O2 和 pH 值波动的实时成像。值得注意的是，这是一个单一的纳米传感系统，通过多色荧光成像能够同时在同一位置可视化多个亚细胞分析物。目前的方法可以为研究活细胞中各种亚细胞分析物的相互作用提供有前途的工具。
