title: Intracellular thiols and photo-illumination sequentially activate doubly locked molecular probes for long-term cell highlighting and tracking with precise spatial accuracy.
abstract: A novel photoconvertible fluorescent probe, which can be activated by intracellular thiols, has been synthesized. Such a molecular probe comprises three parts: a 7-aminocoumarin phototrigger, a thiol-removable energy acceptor, and a caged fluorescein scaffold with intracellular thiols reactivity as the fluorescent reporter. Extracellularly, the energy acceptor blocks the emission of the coumarin that regulates the photocleavage and photoactivation of the fluorescein. Intracelluarly, the high concentration of thiols releases the energy acceptor, thus activating the S1 state of the phototrigger, which emits coumarin blue fluorescence for pre-visualization and liberates the caged green-fluorescent fluorescein to highlight the specific cell upon illumination. Compared to traditional photoactivated organic dyes, the intracellular thiols activated probe requires double activations: one by intracellular thiols and the other by light activation. The dual activations restrict fluorescence precisely inside live cells and at the particular spatial region of light activation, thus a probe with precise spatial accuracy in live cells.
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry, Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237 (P. R. China).
authors.forename: Qiuning
authors.initials: Q
authors.lastname: Lin
authors.forename: Zengmin
authors.initials: Z
authors.lastname: Du
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Fang
authors.forename: Chunyan
authors.initials: C
authors.lastname: Bao
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Linyong
authors.initials: L
authors.lastname: Zhu
mesh_terms: D058948:Cell Tracking / Q000379:methods; D003374:Coumarins / Q000737:chemistry*; D019793:Fluorescein / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008027:Light; D055668:Photochemical Processes; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; D013438:Sulfhydryl Compounds; C080488:7-aminocoumarin; D019793:Fluorescein
keywords: cell photolabeling; coumarins; fluoresceins; photoconvertible fluorescence; thiols