title: Fluorescent imaging of acidic compartments in living cells with a high selective novel one-photon ratiometric and two-photon acidic pH probe.
abstract: Fluorescent imaging of acidic compartments in living cells was carried out successfully by a novel molecule (CAE) that contained a pyridine unit and a carbazole core. As the protonation of the pyridine N atom of CAE, pH-dependent absorption and fluorescence properties were shown with a pKa of 5.47 which matches the pH range of intracellular acidic compartments. Moreover, a large Stokes shift, a significant enhancement in ratios of I544 nm/I460 nm and a distinct two-photon turn-on character were exhibited in spectral analysis. Meanwhile, direct intracellular imaging and standard double-staining experiments of CAE and LTR (co-localization coefficient: 0.83) revealed that CAE is an effective one-photon ratiometric and two-photon acidic pH probe for imaging intracellular acidic compartments. The pH distribution pattern of intracellular acidic compartments can be obtained facilely by CAE. In especial, CAE possessed well membrane-permeability, brilliant selectivity among various bioanalyte and excellent counterstain compatibility with Hoechst 33342, MTR and LTR.
authors.affiliation: Center of Bio & Micro/Nano Functional Materials, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Miao
authors.forename: Guofen
authors.initials: G
authors.lastname: Song
authors.forename: Yuming
authors.initials: Y
authors.lastname: Sun
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Guo
authors.forename: Weijia
authors.initials: W
authors.lastname: Zhang
authors.forename: Minggang
authors.initials: M
authors.lastname: Tian
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Yu
mesh_terms: D000143:Acids / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods; D002227:Carbazoles / Q000737:chemistry*; D002470:Cell Survival; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061848:Optical Imaging / Q000379:methods*
chemical_list: D000143:Acids; D002227:Carbazoles; D005456:Fluorescent Dyes; C041514:carbazole
keywords: Acidic compartments; Bioimaging; Fluorescent pH probe; Ratiometric; Two-photon