title: Highly Selective Two-Photon Fluorescent Probe for Ratiometric Sensing and Imaging Cysteine in Mitochondria.
abstract: 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.
authors.affiliation: Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University , Taiyuan 030006, People's Republic of China.
authors.forename: Weifen
authors.initials: W
authors.lastname: Niu
authors.affiliation: Department of Chemistry and Institute of Molecular Functional Materials, Hong Kong Baptist University , Hong Kong SAR, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Chemistry and Institute of Molecular Functional Materials, Hong Kong Baptist University , Hong Kong SAR, People's Republic of China.|State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, People's Republic of China.
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University , Taiyuan 030006, People's Republic of China.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Shuang
authors.affiliation: Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University , Taiyuan 030006, People's Republic of China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.affiliation: 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.
authors.forename: Man Shing
authors.initials: MS
authors.lastname: Wong
mesh_terms: D000818:Animals; D002470:Cell Survival; D003545:Cysteine / Q000032:analysis*; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000737:chemistry*; D015394:Molecular Structure; D017785:Photons
chemical_list: D005456:Fluorescent Dyes; D003545:Cysteine