4 research outputs found
Aggregation-Induced Emission from Fluorophore–Quencher Dyads with Long-Lived Luminescence
Aggregation-induced emission (AIE)
is an important photophysical
phenomenon in molecular materials and has found broad applications
in optoelectronics, bioimaging, and chemosensing. Currently, the majority
of reported AIE-active molecules are based on either propeller-shaped
rotamers or donor–acceptor molecules with strong intramolecular
charge-transfer states. Here, we report a new design motif, where
a fluorophore is covalently tethered to a quencher, to expand the
scope of AIE-active materials. The fluorophore–quencher dyad
(FQD) is nonemissive in solutions due to photoinduced electron-transfer
quenching but becomes luminescent in the solid state. The intrinsic
emission lifetimes are found to be within the microseconds domain
at both room and low temperatures. We performed single-crystal X-ray
diffraction measurement for each of the FQDs as well as theoretical
calculations to account for the possible origin of the long-lived
AIE. These FQDs represent a new class of AIE-active molecules with
potential applications in organic optoelectronics
Oxygen Sensing Difluoroboron β‑Diketonate Polylactide Materials with Tunable Dynamic Ranges for Wound Imaging
Difluoroboron
β-diketonate polyÂ(lactic acid) materials exhibit
both fluorescence (F) and oxygen sensitive room-temperature phosphorescence
(RTP). Introduction of halide heavy atoms (Br and I) is an effective
strategy to control the oxygen sensitivity in these materials. A series
of naphthyl-phenyl (nbm) dye derivatives with hydrogen, bromide, and
iodide substituents were prepared for comparison. As nanoparticles,
the hydrogen derivative was hypersensitive to oxygen (0–0.3%),
while the bromide analogue was suited for hypoxia detection (0–3%
O<sub>2</sub>). The iodo derivative, BF<sub>2</sub>nbmÂ(I)ÂPLA, showed
excellent F to RTP peak separation and a 0–100% oxygen sensitivity
range, unprecedented for metal-free RTP emitting materials. Due to
the dual emission and exceptionally long RTP lifetimes of these O<sub>2</sub> sensing materials, a portable, cost-effective camera was
used to quantify oxygen levels via lifetime and red/green/blue (RGB)
ratiometry. The hypersensitive H dye was well matched to lifetime
detection; simultaneous lifetime and ratiometric imaging was possible
for the bromide analogue, whereas the iodide material, with intense
RTP emission and a shorter lifetime, was suited for RGB ratiometry.
To demonstrate the prospects of this camera/material design combination
for bioimaging, iodide boron dye-PLA nanoparticles were applied to
a murine wound model to detect oxygen levels. Surprisingly, wound
oxygen imaging was achieved without covering (i.e., without isolating
from ambient conditions, air). Additionally, wound healing was monitored
via wound size reduction and associated oxygen recovery, from hypoxic
to normoxic. These single-component materials provide a simple tunable
platform for biological oxygen sensing that can be deployed to spatially
resolve oxygen in a variety of environments
Oxygen Sensing Difluoroboron β‑Diketonate Polylactide Materials with Tunable Dynamic Ranges for Wound Imaging
Difluoroboron
β-diketonate polyÂ(lactic acid) materials exhibit
both fluorescence (F) and oxygen sensitive room-temperature phosphorescence
(RTP). Introduction of halide heavy atoms (Br and I) is an effective
strategy to control the oxygen sensitivity in these materials. A series
of naphthyl-phenyl (nbm) dye derivatives with hydrogen, bromide, and
iodide substituents were prepared for comparison. As nanoparticles,
the hydrogen derivative was hypersensitive to oxygen (0–0.3%),
while the bromide analogue was suited for hypoxia detection (0–3%
O<sub>2</sub>). The iodo derivative, BF<sub>2</sub>nbmÂ(I)ÂPLA, showed
excellent F to RTP peak separation and a 0–100% oxygen sensitivity
range, unprecedented for metal-free RTP emitting materials. Due to
the dual emission and exceptionally long RTP lifetimes of these O<sub>2</sub> sensing materials, a portable, cost-effective camera was
used to quantify oxygen levels via lifetime and red/green/blue (RGB)
ratiometry. The hypersensitive H dye was well matched to lifetime
detection; simultaneous lifetime and ratiometric imaging was possible
for the bromide analogue, whereas the iodide material, with intense
RTP emission and a shorter lifetime, was suited for RGB ratiometry.
To demonstrate the prospects of this camera/material design combination
for bioimaging, iodide boron dye-PLA nanoparticles were applied to
a murine wound model to detect oxygen levels. Surprisingly, wound
oxygen imaging was achieved without covering (i.e., without isolating
from ambient conditions, air). Additionally, wound healing was monitored
via wound size reduction and associated oxygen recovery, from hypoxic
to normoxic. These single-component materials provide a simple tunable
platform for biological oxygen sensing that can be deployed to spatially
resolve oxygen in a variety of environments
Oxygen Sensing Difluoroboron β‑Diketonate Polylactide Materials with Tunable Dynamic Ranges for Wound Imaging
Difluoroboron
β-diketonate polyÂ(lactic acid) materials exhibit
both fluorescence (F) and oxygen sensitive room-temperature phosphorescence
(RTP). Introduction of halide heavy atoms (Br and I) is an effective
strategy to control the oxygen sensitivity in these materials. A series
of naphthyl-phenyl (nbm) dye derivatives with hydrogen, bromide, and
iodide substituents were prepared for comparison. As nanoparticles,
the hydrogen derivative was hypersensitive to oxygen (0–0.3%),
while the bromide analogue was suited for hypoxia detection (0–3%
O<sub>2</sub>). The iodo derivative, BF<sub>2</sub>nbmÂ(I)ÂPLA, showed
excellent F to RTP peak separation and a 0–100% oxygen sensitivity
range, unprecedented for metal-free RTP emitting materials. Due to
the dual emission and exceptionally long RTP lifetimes of these O<sub>2</sub> sensing materials, a portable, cost-effective camera was
used to quantify oxygen levels via lifetime and red/green/blue (RGB)
ratiometry. The hypersensitive H dye was well matched to lifetime
detection; simultaneous lifetime and ratiometric imaging was possible
for the bromide analogue, whereas the iodide material, with intense
RTP emission and a shorter lifetime, was suited for RGB ratiometry.
To demonstrate the prospects of this camera/material design combination
for bioimaging, iodide boron dye-PLA nanoparticles were applied to
a murine wound model to detect oxygen levels. Surprisingly, wound
oxygen imaging was achieved without covering (i.e., without isolating
from ambient conditions, air). Additionally, wound healing was monitored
via wound size reduction and associated oxygen recovery, from hypoxic
to normoxic. These single-component materials provide a simple tunable
platform for biological oxygen sensing that can be deployed to spatially
resolve oxygen in a variety of environments