Niu Weifen, Guo Lei, Li Yinhui, Shuang Shaomin, Dong Chuan, Wong Man Shing
Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University , Taiyuan 030006, People's Republic of China.
Department of Chemistry and Institute of Molecular Functional Materials, Hong Kong Baptist University , Hong Kong SAR, People's Republic of China.
Anal Chem. 2016 Feb 2;88(3):1908-14. doi: 10.1021/acs.analchem.5b04329. Epub 2016 Jan 8.
A novel ratiometric mitochondrial cysteine (Cys)-selective two-photon fluorescence probe has been developed on the basis of a merocyanine as the fluorophore and an acrylate moiety as the biothiol reaction site. The biocompatible and photostable acrylate-functionalized merocyanine probe shows not only a mitochondria-targeting property but also highly selective detection and monitoring of Cys over other biothiols such as homocysteine (Hcy) and glutathione (GSH) and hydrogen sulfide (H2S) in live cells. In addition, this probe exhibits ratiometric fluorescence emission characteristics (F518/F452), which are linearly proportional to Cys concentrations in the range of 0.5-40 μM. More importantly, the probe and its released fluorophore, merocyanine, exhibit strong two-photon excited fluorescence (TPEF) with two-photon action cross-section (Φσmax) of 65.2 GM at 740 nm and 72.6 GM at 760 nm in aqueous medium, respectively, which is highly desirable for high contrast and brightness ratiometric two-photon fluorescence imaging of the living samples. The probe has been successfully applied to ratiometrically image and detect mitochondrial Cys in live cells and intact tissues down to a depth of 150 μm by two-photon fluorescence microscopy. Thus, this ratiometric two-photon fluorescent probe is practically useful for an investigation of Cys in living biological systems.
基于部花青作为荧光团和丙烯酸酯部分作为生物硫醇反应位点，开发了一种新型的比率型线粒体半胱氨酸（Cys）选择性双光子荧光探针。这种具有生物相容性和光稳定性的丙烯酸酯功能化部花青探针不仅具有线粒体靶向特性，而且在活细胞中对Cys的检测和监测具有高度选择性，优于其他生物硫醇，如高半胱氨酸（Hcy）、谷胱甘肽（GSH）和硫化氢（H2S）。此外，该探针表现出比率荧光发射特性（F518/F452），在0.5 - 40 μM范围内与Cys浓度呈线性比例关系。更重要的是，该探针及其释放的荧光团部花青在水性介质中分别表现出强烈的双光子激发荧光（TPEF），在740 nm处的双光子作用截面（Φσmax）为65.2 GM，在760 nm处为72.6 GM，这对于活体样品的高对比度和高亮度比率型双光子荧光成像非常理想。该探针已成功应用于通过双光子荧光显微镜对活细胞和完整组织中线粒体Cys进行比率成像和检测，深度可达150 μm。因此，这种比率型双光子荧光探针在研究活生物系统中的Cys方面具有实际应用价值。
