ACS Applied Nano Materials,
Год журнала:
2024,
Номер
7(9), С. 10591 - 10599
Опубликована: Апрель 22, 2024
Exciton-recombination
probability
is
an
important
factor
that
affects
the
fluorescence
efficiency
of
semiconductor
nanocrystal
quantum
dots
(QDs),
especially
those
exhibit
near-infrared
(NIR)
luminescence,
making
their
performances
modulated
via
modification
some
receptors.
Herein,
we
present
a
novel
and
facile
method
for
consumption
trace
l-cysteine
(l-Cys)
under
physiological
conditions
by
using
atomically
dispersed
gold
modified
cadmium
sulfide
QDs
(sAu/CdS
QDs)
with
remarkably
enhanced
NIR
compared
to
free
CdS
QDs.
The
enhancement
ascribed
electron
transfer
from
single-atom
Au,
increasing
recombination
conduction
band
electrons
valence
holes
decreasing
lifetime.
Nevertheless,
electronic
state
density
Au
on
increased
upon
its
coordination
l-Cys
as
donor,
which
restricts
decrease
exciton-recombination
increase
lifetime
again,
partially
lowering
efficiency.
change
makes
sAu/CdS
promising
candidates
effective
good
anti-interference
against
other
various
biologically
relevant
species
extremely
high
sensitivity,
limit
detection
(LOD)
down
8.10
nM,
successfully
applied
in
practical
applicability
consuming
real
water
samples.
Our
results
broaden
application
potential
luminescent
theoretical
guidance
technical
support
provide
approach
consume
through
modulation
efficiency,
would
be
useful
diagnosing
treating
series
l-Cys-induced
diseases.
Particle & Particle Systems Characterization,
Год журнала:
2021,
Номер
38(11)
Опубликована: Сен. 13, 2021
Abstract
Carbon
quantum
dots
(CQDs)
are
a
unique
class
of
0D
nanomaterials,
featured
by
graphitic
core
and
shell
layers
saturated
with
hydrogen
atoms
functional
groups.
CQDs
prepared
through
top‐down
bottom‐up
strategies
from
natural
synthetic
precursors.
can
be
modified
chemical
(e.g.,
surface
functionalization/passivation,
doping,
etc.)
physical
core–shell
architecture,
composite
material
blending,
to
control
their
properties.
This
review
highlights
the
effect
such
modifications
on
photophysical
properties
CQDs,
as
photoluminescence
(PL),
absorbance,
relaxivity.
The
dependence
PL
upon
size,
orientation
at
edges,
edge
functionalization,
excitation
wavelength,
concentration,
pH,
aggregate
formation,
etc.,
summarized
along
supporting
theoretical
evidence
available
in
literature.
Also,
this
outlines
recent
advancements,
future
prospective
optical
sensing,
bioimaging,
fluorescent
ink)
catalytic
applications
photocatalysis
electrocatalysis)
enhanced
structure
composition.
Abstract
Because
of
their
prospective
applications
and
exceptional
features,
graphene
quantum
dots
(GQDs)
have
gotten
a
lot
recognition
as
new
class
fluorescent
carbon
materials.
One
the
family’s
newest
superstars
is
GQD.
Due
to
its
optoelectrical
qualities,
it
has
sparked
curiosity
since
debut
in
2008.
Two
most
important
traits
are
band
gap
that
not
zero,
biocompatibility,
highly
changeable
characteristics.
GQDs
several
shown
potential
variety
fields,
for
instance,
catalysis,
sensing,
energy
devices,
drug
delivery,
bioimaging,
photothermal,
photodynamic
therapy.
this
area
constantly
evolves,
vital
recognize
emerging
GQD
concerns
current
breakthroughs,
primarily
some
specific
uses
developments
case
synthesis
been
thoroughly
investigated
through
previous
studies.
The
results
properties,
synthesis,
well
benefits
discussed
review
study.
As
per
findings
research,
GQD’s
future
investigation
boundless,
mainly
if
approaching
focuses
on
purifying
simplicity
environmentally
friendly
boosting
photoluminescence
output
manufacturing
GQDs.
Urea
is
a
typical
contaminant
present
in
wastewater
which
may
cause
severe
environmental
problems.
Electrochemical
catalytic
oxidation
of
urea
has
emerged
as
an
efficient
approach
to
solve
this
problem.
Nevertheless,
the
current
nickel-based
catalysts
(e.g.,
nickel
hydroxide/sulfides)
feature
high
metal
content.
It
not
only
lowers
utilization
efficiency
but
also
causes
secondary
pollution
environment.
Here,
nickel-doped
carbon
dots
(Ni-CDs)
with
excellent
and
stable
activity
for
electrocatalytic
reaction
(UOR)
are
reported.
Specifically,
(CDs)
abundant
functional
groups
synthesized
by
one-pot
hydrothermal
method
then
Ni-CDs
very
low
content
(1.1
at%)
prepared.
The
Ni2+
sites
coordination
carboxylic
on
CDs
provide
durability
UOR,
demonstrated
anodic
density
100
mA
cm-2
at
potential
1.38
V
(vs
RHE)
similar
experimental
results
practical
application.
To
best
knowledge,
first
report
CDs-based
materials
applied
opens
important
new
area
applicability
well
broadens
scope
electrochemical
catalysis
urea.
Scientific Reports,
Год журнала:
2022,
Номер
12(1)
Опубликована: Окт. 21, 2022
In
this
research
passivated
gadolinium-doped
carbon
quantum
dots
(Gd-doped
CQDs)
were
synthesized
from
starch
by
a
hydrothermal
method.
The
X-ray
diffraction
(XRD)
pattern
of
the
Gd-doped
CQDs
showed
formation
highly
amorphous
carbon.
Fourier
transform
infrared
spectroscopy
(FTIR)
results
suggested
that
are
functionalized
with
C-N
and
N-H
bonds.
size
distribution
2-8
nm
have
an
absorption
peak
at
271
in
UV-Visible
(UV-Vis).
photoluminescence
(PL)
was
dependent
on
excitation
wavelength.
QY
calculated
to
be
13.2%.
exhibited
sustained
PL
ionic
solutions
different
strengths
temperatures
up
65
°C.
Fluorescence
imaging
mouse
C34/connective
tissue-L929
cells
confirmed
could
well
distributed
over
cytoplasm.
magnetic
resonance
(MRI)
extremely
high
longitudinal
transverse
relaxivity
values
as
218.28
mM-1
s-1
364.68
s-1.
promising
candidates
multifunctional
probes
MRI
contrast
agents
biomedical
diagnosis
brain
mapping
applications.
Carbon
Dots
(CDs)
are
luminescent
quasi-spherical
nanoparticles,
possessing
water
solubility,
high
biocompatibility,
and
tunable
chemical
physical
properties
for
a
wide
range
of
applications,
including
nanomedicine
theranostics.
The
evaluation
new
purification
criteria,
useful
to
achieve
more
reliable
CDs,
free
from
the
interference
artifacts,
is
currently
an
object
debate
in
field.
Here,
CDs
doped
with
gadolinium
(Gd
(III)),
named
Gd@CNDs,
presented
as
multifunctional
probes
Magnetic
Resonance
Imaging
(MRI).
This
system
case
study,
evaluate
and/or
combine
different
strategies,
crucial
approach
generate
better
performance.
Indeed,
these
amorphous
Gd@CNDs
display
good
homogeneity,
they
emissive
side
products.
(7-10
nm)
contain
7%
Gd
(III)
w/w,
suitable
stable
longitudinal
relaxivity
(r1
)
behavior,
therefore
potentially
both
MR
fluorescence
imaging.
They
show
biocompatibility
cellular
vivo
studies,
cell
permeability,
ability
contrast
pellets.
Finally,
MRI
recording
T1
-weighted
images
on
mice
after
intravenous
injection
signal
enhancement
liver,
spleen,
kidney
30
min
postinjection.
ACS Applied Nano Materials,
Год журнала:
2022,
Номер
5(8), С. 10151 - 10166
Опубликована: Авг. 9, 2022
Today,
magnetic
resonance
imaging
(MRI)
is
one
of
the
most
widely
applied
noninvasive
clinical
modalities
with
excellent
applicability
in
bio-
and
nanomedicine,
particularly
specific
detecting
high-quality
three-dimensional
tumors/cancers.
In
this
context,
design
efficient
nanoscale
contrast
agents
(NCAs)
for
MRI
high
relaxivity
specificity/selectivity
has
garnered
immense
interest
deploying
a
variety
innovatively
designed
nanostructures.
Some
important
characteristics
NCAs
such
as
biocompatibility,
improved
relaxivity,
dispersibility,
targeting,
low
toxicity
make
them
ideal
candidates
imaging/biosensing
applications.
The
hybridization
surface
functionalization/modification
these
materials
by
applying
suitable
functional
groups/agents
can
help
to
improve
their
properties
multifunctionality.
However,
there
still
long
way
go
applications
nanoagents
serve
substitute
Gd-based
or
other
commercial
materials.
Importantly,
nanotoxicological
biosafety
issues
need
be
systematically
addressed
both
at
pre-
stages;
construction
smart
multifunctional
diagnostic
potentials
thus
warranted.
Herein,
recent
advancements
related
are
deliberated,
focusing
on
challenges
future
directions.
