title: 2D ratiometric fluorescent pH sensor for tracking of cells proliferation and metabolism.
abstract: Extracellular pH plays a vital role no matter in physiological or pathological studies. In this work, a hydrogel, CD@Nile-FITC@Gel (Gel sensor), entrapping the ratiometric fluorescent probe CD@Nile-FITC was developed. The Gel sensor was successfully used for real-time extracellular pH monitoring. In the case of CD@Nile-FITC, pH-sensitive fluorescent dye fluorescein isothiocyanate (FITC) was chosen as the response signal for H(+) and Nile blue chloride (Nile) as the reference signal. The developed fluorescent probe exhibited high selectivity for pH over other metal ions and amino acids. Meanwhile, the carbon-dots-based inorganic-organic probe demonstrated excellent photostability against long-term light illumination. In order to study the extracellular pH change in processes of cell proliferation and metabolism, CD@Nile-FITC probe was entrapped in sodium alginate gel and consequently formed CD@Nile-FITC@Gel. The MTT assay showed low cytotoxicity of the Gel and the pH titration indicated that it could monitor the pH fluctuations linearly and rapidly within the pH range of 6.0-9.0, which is valuable for physiological pH determination. As expected, the real-time bioimaging of the probe was successfully achieved.
authors.affiliation: Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China.
authors.forename: Changqin
authors.initials: C
authors.lastname: Ding
authors.affiliation: Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China; Department of Chemistry, East China Normal University, North Zhongshan Road 3663, Shanghai 200062, PR China. Electronic address: ytian@chem.ecnu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Tian
mesh_terms: D049109:Cell Proliferation / Q000502:physiology; D058948:Cell Tracking / Q000379:methods*; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D010078:Oxazines / Q000737:chemistry; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013347:Subcellular Fractions / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure*
chemical_list: D005456:Fluorescent Dyes; D010078:Oxazines; C008619:Nile Blue; D016650:Fluorescein-5-isothiocyanate
keywords: Fluorescent probe; Hydrogel; Live cells; PH sensor; Ratiometric