title: Targeted surface-functionalized gold nanoclusters for mitochondrial imaging.
abstract: Due to mitochondria involved in both apoptotic and necrotic cell death, labeling and imaging mitochondria has attracted considerable interest. However, conventional organic dyes used for mitochondrial imaging are limited because of their poor photostability. Considering that gold nanoclusters (AuNCs) possess some advantages over considerable interest, such as excellent photostability and strong fluorescence emission, we herein prepared a mitochondria-targeted fluorescent probe, AuNCs@CS-TPP, based on a covalent link between triphenylphosphonium (TPP) cations and chitosan-coated AuNCs (AuNCs@CS). The as-prepared AuNCs@CS-TPP exhibited a bluish fluorescence emission at 440 nm with a quantum yield of 8.5%. Meanwhile, the fluorescence intensity of AuNCs@CS-TPP labeled HeLa cells did not show apparent decrease after 8 min irradiation. Cytotoxicity assay showed that AuNCs@CS-TPP did not display any appreciable cytotoxicity on cells even at a concentration of 60 μg mL(-1). In addition, the result of fluorescence co-localization imaging in vitro indicated that AuNCs@CS-TPP could selectively accumulate into mitochondria of HeLa cells and HepG2 cells. These findings demonstrated that AuNCs@CS-TPP possessed superior photostability, low cytotoxicity, high sensitivity and target-specificity to mitochondria, allowing labeling and imaging of the mitochondria in living cells.
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China; Graduate School, University of Chinese Academy of Sciences, 100049 Beijing, China.
authors.forename: Qianfen
authors.initials: Q
authors.lastname: Zhuang
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Jia
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Du
authors.affiliation: Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, 050024 Shijiazhuang, China.
authors.forename: Yanchao
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China; Graduate School, University of Chinese Academy of Sciences, 100049 Beijing, China.
authors.forename: Saipeng
authors.initials: S
authors.lastname: Huang
authors.affiliation: State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, China. Electronic address: yliu@iccas.ac.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D003287:Contrast Media / Q000138:chemical synthesis; D005456:Fluorescent Dyes / Q000138:chemical synthesis; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D008856:Microscopy, Fluorescence / Q000379:methods*; D008928:Mitochondria / Q000648:ultrastructure*; D053769:Nanocapsules / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes; D053769:Nanocapsules; D006046:Gold
keywords: Chitosan; Fluorescence; Gold nanoclusters; Mitochondria; Mitochondrial imaging; Triphenylphosphonium