title: Oxygen Sensing Difluoroboron Dinaphthoylmethane Polylactide.
abstract: Dual emissive luminescence properties of solid-state difluoroboron β-diketonate-poly(lactic acid) (BF2bdk-PLA) materials have been utilized as biological oxygen sensors. Dyes with red-shifted absorption and emission are important for multiplexing andin vivoimaging, thus hydroxyl-functionalized dinaphthoylmethane initiators and dye-PLA conjugates BF2dnm(X)PLA (X = H, Br, I) with extended conjugation were synthesized. The luminescent materials show red-shifted absorbance (~435 nm) and fluorescence tunability by molecular weight. Fluorescence colors range from yellow (~530 nm) in 10 - 12 kDa polymers to green (~490 nm) in 20 - 30 kDa polymers. Room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) are present under a nitrogen atmosphere. For the iodine-substituted derivative, BF2dnm(I)PLA, clearly distinguishable fluorescence (green) and phosphorescence (orange) peaks are present, making it ideal for ratiometric oxygen-sensing and imaging. Bromide and hydrogen analogues with weaker relative phosphorescence intensities and longer phosphorescence lifetimes can be used as highly sensitive, concentration independent, lifetime-based oxygen sensors or for gated emission detection. BF2dnm(I)PLA nanoparticles were taken up by T41 mouse mammary cells and successfully demonstrated differencesin vitroratiometric measurement of oxygen.
authors.affiliation: Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: DeRosa
authors.affiliation: Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904.
authors.forename: Jelena
authors.initials: J
authors.lastname: Samonina-Kosicka
authors.affiliation: Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham NC, 27710.
authors.forename: Hansford C
authors.initials: HC
authors.lastname: Hendargo
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham NC, 27710.
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Weitzel
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham NC, 27710.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Palmer
authors.affiliation: Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904.
authors.forename: Cassandra L
authors.initials: CL
authors.lastname: Fraser
keywords: Difluoroboron β-diketonate complexes; heavy-atom effect; oxygen-sensitive material; poly(lactic-acid); room-temperature phosphorescence (RTP); thermally activated delayed fluorescence (TADF)