6 research outputs found
Oxygen Sensing Difluoroboron Dinaphthoylmethane Polylactide
Dual
emissive properties of solid-state difluoroboron β-diketonate-polyÂ(lactic
acid) (BF<sub>2</sub>bdk-PLA) materials have been utilized as biological
oxygen sensors. Dyes with red-shifted absorption and emission are
important for multiplexing and <i>in vivo</i> imaging, thus
hydroxyl-functionalized dinaphthoylmethane initiators and dye-PLA
conjugates BF<sub>2</sub>dnmÂ(X)ÂPLA (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, BF<sub>2</sub>dnmÂ(I)ÂPLA, 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. BF<sub>2</sub>dnmÂ(I)ÂPLA nanoparticles were taken
up by T41 mouse mammary cells and successfully detected differences in oxygen levels during <i>in vitro</i> ratiometric imaging