2 research outputs found
A BODIPY-Based Fluorescent Probe for Detection of Subnanomolar Phosgene with Rapid Response and High Selectivity
A new
type of phosgene probe with a limit of detection down to 0.12 nM,
response time of less than 1.5 s, and high selectivity over other
similarly reactive toxic chemicals was developed using ethylenediamine
as the recognition moiety and 8-substituted BODIPY unit as the fluorescence
signaling component. The probe undergoes sequential phosgene-mediated
nucleophilic substitution reaction and intramolecular cyclization
reaction with high rate, yielding a product with the intramolecular
charge transfer (ICT) process from amine to the BODIPY core significantly
inhibited. Owing to the emission feature of 8-substituted BODIPY that
is highly sensitive to the substituent′s electronic nature,
such inhibition on the ICT process strikingly generates strong fluorescence
contrast by a factor of more than 23 300, and therefore creates
the superhigh sensitivity of the probe for phosgene. Owing to the
high reactivity of ethylenediamine of the probe in nucleophilic substitution
reactions, the probe displays a very fast response rate to phosgene
A Turn-On Fluorescent Probe for Detection of Sub-ppm Levels of a Sulfur Mustard Simulant with High Selectivity
A new
type of fluorescent probe capable of detecting a sulfur mustard
(SM) simultant at a concentration of 1.2 μM in solution and
0.5 ppm in the gas phase has been developed. Owing to its molecular
structure with a thiocarbonyl component and two piperidyl moieties
integrated into the xanthene molecular skeleton, this probe underwent
a highly selective nucleophilic reaction with the SM simultant and
generated a thiopyronin derivative emitting intensive pink fluorescence.
The distinct difference in electronic structure between the probe
and thiopyronin derivative generated a marked shift of the absorption
band from 445 to 567 nm, which enabled an optimal wavelength propitious
for exciting the thiopyronin derivative but adverse to the probe.
Such efficient separation of the excitation wavelength and tremendous
increase in fluorescence quantum yield, from less than 0.002 to 0.53,
upon conversion from the probe to the thiopyronin derivative, jointly
led to a distinct contrast in the beaconing fluorescence signal (up
to 850-fold) and therefore the unprecedented sensitivity for detecting
SM species