title: BODIPY-based oligo(ethylene glycol) dendrons as fluorescence thermometers: when thermoresponsiveness meets intramolecular electron/charge transfer.
abstract: The temperature-dependent photophysical properties of a series of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives with different oligo(ethylene glycol) (OEG) dendrons were investigated. Weak fluorescence emission was observed for these BODIPY derivatives in dilute solution with low viscosity. BDP-G0 and BDP-G1-TEG exhibit a high quantum yield in viscous glycerol solutions, contrary to the moderate and little fluorescence enhancement for BDP-G1 and BDP-G2 under the same conditions. The photoinduced electron transfer (PET) may have quenched the fluorescence, as supported by calculation. Interestingly, the thermoresponsive BODIPY derivatives show heat-induced luminescence enhancement with a high signal-to-noise ratio and their emission maxima are dependent on the structures of branched tri(ethylene glycol) moieties. Finally, preliminary studies on the BODIPY derivatives as intracellular fluorescence indicators in living HeLa cells were carried out.
authors.affiliation: Department of Polymer Materials, Shanghai University, Nanchen Road 333, 200444, Shanghai (P.R. China).
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Wu
authors.forename: Pan
authors.initials: P
authors.lastname: Tao
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.forename: Gui-Chao
authors.initials: GC
authors.lastname: Kuang
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D050091:Dendrimers / Q000737:chemistry*; D004583:Electrons; D019855:Ethylene Glycol / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D061848:Optical Imaging; D013696:Temperature; D013821:Thermometers
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D050091:Dendrimers; D005456:Fluorescent Dyes; D019855:Ethylene Glycol
keywords: BODIPY; dendrimers; fluorescence; imaging agents; thermoresponsiveness