title: Full-range intracellular pH sensing by an aggregation-induced emission-active two-channel ratiometric fluorogen.
abstract: Intracellular pH (pHi) is an important parameter associated with cellular behaviors and pathological conditions. Sensing pHi and monitoring its changes in live cells are essential but challenging due to the lack of effective probes. We herein report a pH-sensitive fluorogen for pHi sensing and tracking. The dye is a tetraphenylethene-cyanine adduct (TPE-Cy). It is biocompatible and cell-permeable. Upon diffusing into cells, it responds sensitively to pHi in the entire physiological range, visualizing the acidic and basic compartments with intense red and blue emissions, respectively. The ratiometric signal of the red and blue channels can thus serve as an indicator for local proton concentration. The utility of TPE-Cy in pHi imaging and monitoring is demonstrated with the use of confocal microscopy, ratiometric analysis, and flow cytometry.
authors.affiliation: Division of Biomedical Engineering, Department of Chemistry, Institute for Advanced Study, and Institute of Molecular Functional Materials, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Sijie
authors.initials: S
authors.lastname: Chen
authors.forename: Yuning
authors.initials: Y
authors.lastname: Hong
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Jianzhao
authors.initials: J
authors.lastname: Liu
authors.forename: Chris W T
authors.initials: CW
authors.lastname: Leung
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Ryan T K
authors.initials: RT
authors.lastname: Kwok
authors.forename: Engui
authors.initials: E
authors.lastname: Zhao
authors.forename: Jacky W Y
authors.initials: JW
authors.lastname: Lam
authors.forename: Yong
authors.initials: Y
authors.lastname: Yu
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000737:chemistry*; D018613:Microscopy, Confocal; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence
chemical_list: D017738:Alkanesulfonic Acids; D005456:Fluorescent Dyes; D007211:Indoles; C000592279:TPE-Cy-H