title: Nanoscale metal-organic frameworks for real-time intracellular pH sensing in live cells.
abstract: Real-time measurement of intracellular pH in live cells is of great importance for understanding physiological/pathological processes and developing intracellular drug delivery systems. We report here the first use of nanoscale metal-organic frameworks (NMOFs) for intracellular pH sensing in live cells. Fluorescein isothiocyanate (FITC) was covalently conjugated to a UiO NMOF to afford F-UiO NMOFs with exceptionally high FITC loadings, efficient fluorescence, and excellent ratiometric pH-sensing properties. Upon rapid and efficient endocytosis, F-UiO remained structurally intact inside endosomes. Live cell imaging studies revealed endo- and exocytosis of F-UiO and endosome acidification in real time. Fluorescently labeled NMOFs thus represent a new class of nanosensors for intracellular pH sensing and provide an excellent tool for studying NMOF-cell interactions.
authors.affiliation: Department of Chemistry, University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Chunbai
authors.initials: C
authors.lastname: He
authors.forename: Kuangda
authors.initials: K
authors.lastname: Lu
authors.forename: Wenbin
authors.initials: W
authors.lastname: Lin
mesh_terms: D015374:Biosensing Techniques; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000737:chemistry*; D011992:Endosomes / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D009942:Organometallic Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D009942:Organometallic Compounds; D016650:Fluorescein-5-isothiocyanate