title: Background-free in-vivo Imaging of Vitamin C using Time-gateable Responsive Probe.
abstract: Sensitive optical imaging of active biomolecules in the living organism requires both a molecular probe specifically responsive to the target and a high-contrast approach to remove the background interference from autofluorescence and light scatterings. Here, a responsive probe for ascorbic acid (vitamin C) has been developed by conjugating two nitroxide radicals with a long-lived luminescent europium complex. The nitroxide radical withholds the probe on its "off" state (barely luminescent), until the presence of vitamin C will switch on the probe by forming its hydroxylamine derivative. The probe showed a linear response to vitamin C concentration with a detection limit of 9.1 nM, two orders of magnitude lower than that achieved using electrochemical methods. Time-gated luminescence microscopy (TGLM) method has further enabled real-time, specific and background-free monitoring of cellular uptake or endogenous production of vitamin C, and mapping of vitamin C in living Daphnia magna. This work suggests a rational design of lanthanide complexes for background-free small animal imaging of biologically functional molecules.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry,Dalian University of Technology, Dalian 116024, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry,Dalian University of Technology, Dalian 116024, P. R. China.
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Ye
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry,Dalian University of Technology, Dalian 116024, P. R. China.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry,Dalian University of Technology, Dalian 116024, P. R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Ma
authors.affiliation: Advanced Cytometry Labs, ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP),Macquarie University, NSW 2109, Sydney, Australia.
authors.forename: Xianlin
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Advanced Cytometry Labs, ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP),Macquarie University, NSW 2109, Sydney, Australia.
authors.forename: Dayong
authors.initials: D
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry,Dalian University of Technology, Dalian 116024, P. R. China.
authors.forename: Jingli
authors.initials: J
authors.lastname: Yuan
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D002460:Cell Line; D003621:Daphnia; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008163:Luminescent Measurements / Q000379:methods; D008856:Microscopy, Fluorescence; D015335:Molecular Probes; D061848:Optical Imaging / Q000379:methods*
chemical_list: D015335:Molecular Probes; D001205:Ascorbic Acid