Molecules,
Journal Year:
2024,
Volume and Issue:
29(13), P. 3000 - 3000
Published: June 24, 2024
The
sensitivity
of
immunoassays
is
generally
limited
by
the
low
signal
reporter/recognition
element
ratio.
Nanomaterials
serving
as
carriers
can
enhance
loading
number
reporters,
thus
improving
detection
sensitivity.
However,
general
immobilization
strategies,
including
direct
physical
adsorption
and
covalent
coupling,
may
cause
random
orientation
conformational
change
in
proteins,
partially
or
completely
suppressing
enzymatic
activity
molecular
recognition
ability.
In
this
work,
we
proposed
a
strategy
to
load
elements
antibodies
enzyme
labels
using
boronic
acid-modified
metal-organic
frameworks
(MOFs)
nanocarriers
for
amplification.
conjugation
was
based
on
boronate
ester
interactions
between
carbohydrate
moieties
enzymes
acid
MOFs.
Both
MOFs
could
catalyze
oxidation
3,3′,5,5′-tetramethylbenzidine
(TMB)
H2O2,
therefore
achieving
dual
To
indicate
feasibility
strategy,
colorimetric
prostate
specific
antigen
(PSA)
were
performed
with
Cu-MOFs
peroxidase
mimics
TMB
antibody
(horseradish
peroxidase,
HRP).
According
absorbance
intensity
oxidized
(oxTMB),
PSA
at
concentration
range
1~250
pg/mL
be
readily
determined.
addition,
work
presented
site-specific
oriented
modification
nanolabels
which
should
valuable
design
novel
biosensors
high
selectivity.
Analytical Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 19, 2025
The
wash-free
method
represents
a
promising
strategy
for
enhancing
the
detection
efficiency
of
automated
chemiluminescent
(CL)
immunoassay
analyzers.
Herein,
novel
separation-free
and
was
developed
first
time
based
on
distance-driven
CL
technique.
In
immunoassay,
well-designed
Au–Co
metal
nanoclusters
(NCs)
exhibited
excellent
peroxidase-like
activity
good
stability,
allowing
efficient
catalysis
luminol
or
its
analogue
(ABEI)-H2O2
system
even
at
low
concentrations.
Furthermore,
large
specific
surface
area
NCs
facilitated
accommodation
greater
number
antibodies,
thereby
capture
antigens
achieving
dual
amplification
signal.
technique
relied
formation
sandwich-type
immunocomplexes.
Upon
generation
hydroxyl
radicals
superoxide
anion
through
catalytic
decomposition
H2O2
by
NCs,
ABEI
within
immunocomplexes
could
efficiently
react
with
these
radicals,
leading
to
significant
enhancement
in
signals.
C-reactive
protein
(CRP)
chosen
as
model
analyte
evaluate
practicability
proposed
immunoassay.
Notably,
presented
high
sensitivity,
selectivity,
reproducibility,
successfully
determining
CRP
serum
samples
recoveries
96.55–106.29%.
Accordingly,
advantage
separation-free,
wash-free,
reliable
characteristics
drastically
simplify
operation
steps
enhance
efficiency,
which
would
make
advances
revolution
traditional
Sensors,
Journal Year:
2024,
Volume and Issue:
24(20), P. 6701 - 6701
Published: Oct. 18, 2024
This
work
reported
gold
nanoparticles
(AuNPs)-based
colorimetric
immunoassay
with
the
Cu-based
metal–organic
framework
(MOF)
to
load
pyrroloquinoline
quinone
(PQQ)
for
catalytic
oxidation
of
cysteine.
In
this
method,
both
Cu2+
and
PQQ
in
MOF
could
promote
inducer
cysteine
by
redox
cycling,
thus
limiting
cysteine-induced
aggregation
AuNPs
achieving
dual
signal
amplification.
Specifically,
recombinant
carcinoembryonic
antigen
(CEA)
targets
were
anchored
on
through
metal
coordination
interactions
between
hexahistidine
(His6)
tag
CEA
unsaturated
sites
MOF.
The
CEA/PQQ-loaded
be
captured
antibody-coated
ELISA
plate
catalyze
However,
once
target
samples
bound
antibody
immobilized
surface,
attachment
would
limited.
Cysteine
remaining
solution
trigger
cause
a
color
change
from
red
blue.
concentration
was
positively
related
AuNPs.
signal-on
competitive
plasmonic
exhibited
low
detection
limit
linear
range
0.01–1
ng/mL.
Note
that
most
proteins
commercial
kits
are
His6
N-
or
C-terminal,
so
provide
sensitive
platform
biomarkers.
Biosensors,
Journal Year:
2025,
Volume and Issue:
15(2), P. 65 - 65
Published: Jan. 21, 2025
Vitamin
B12
(VB12)
is
an
important
nutrient,
and
its
quality
control
in
food
crucial.
In
this
study,
based
on
the
principle
of
specific
recognition
target
analyte
by
monoclonal
antibodies
(mAbs),
a
time-resolved
fluorescent
microsphere
immunochromatographic
assay
(TRFM-ICA)
was
developed
to
detect
content
VB12
infant
formula
milk
powder.
First,
performance
anti-VB12
mAb
evaluated,
revealing
half-maximal
inhibitory
concentration
0.370
ng/mL,
affinity
constant
2.604
×
109
L/mol
no
cross-reactivity
with
other
vitamins.
Then,
highly
sensitive
TRFM-ICA
developed,
visual
limit
detection
10
μg/kg
cut-off
value
100
for
qualitative
range
4.125–82.397
quantitative
detection.
addition,
test
results
real
samples
were
consistent
quantification
using
microbiological
methods,
coefficient
variation
less
than
10%,
showing
good
accuracy
stability,
confirming
that
suitable
analysis
powder
samples.
(mAbs)
against
VB12,
fluorescence
converting
biological
signals
into
optical
signals.
ACS Sensors,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 23, 2025
It
is
crucial
yet
challenging
to
sensitively
quantify
low-abundance
biomarkers
in
blood
for
early
screening
and
diagnosis
of
various
diseases.
Herein,
an
analytical
model
intra-mesopore
immunoassay
(IMIA)
was
proposed,
which
competent
examine
at
the
femtomolar
level.
The
success
rooted
design
innovative
superparamagnetic
core-shell
structure
with
Fe3O4
nanoparticles
(NPs)
core
hierarchically
porous
zeolitic
imidazolate
frameworks
as
a
shell
(Fe3O4@HPZIF-8),
achieved
through
soft-template
directed
self-assembly
coupled
confinement
growth
mechanism.
Such
unique
configuration
conceptualized
IMIA
where
HPZIF-8
served
solid
carrier
cover
capture
antibodies
while
assisted
its
rapid
separation.
large
pore
channels
not
only
provided
stable
microenvironment
maintain
recognition
ability
captured
but
also
enhanced
their
coating
density,
thus
promoting
probability
capturing
binding
target
antigens,
significantly
improving
(IA)
sensitivity.
practical
clinic
IA
cTnI
(Cardiac
Troponin
I,
biomarker
acute
myocardial
infarction
(AMI))
human
serums
exemplified.
developed
could
accurately
slight
fluctuations
concentrations
AMI
patients
different
stages
after
symptom
onset
more
than
100-fold
enhancement
limit
detection
(LOD)
comparison
conventional
plate-based
enzyme-linked
immunosorbent
assay
(ELISA).
high
sensitivity
makes
it
powerful
tool
accurate
diseases
by
altering
type
primary
antibody.
Biosensors,
Journal Year:
2025,
Volume and Issue:
15(5), P. 313 - 313
Published: May 14, 2025
Lateral
flow
immunoassay
(LFIA)
is
a
promising
tool
for
rapid
detection
in
the
field
of
agricultural
product
analysis
due
to
its
advantages
cost-effectiveness
and
operational
simplicity.
In
this
work,
Eu
metal-organic
frameworks
(MOFs)
were
introduced
LFIA
as
method
characterized
by
high
stability
low
interference.
Key
research
objectives
included
strong
fluorescence,
ease
labeling,
utilization
fluorescent
probes.
Eu-MOFs
synthesized
one
step
via
hydrothermal
method,
exhibiting
fluorescence
lifetime
163
μs
spherical
particles
with
diameters
ranging
from
250
400
nm.
These
conditions
fulfill
characteristics
requirements
LFIA.
exploit
porous
nature
MOFs
mitigate
drawbacks
associated
complex
crosslinking
agents.
This
enables
antibody
proteins
be
cross-linked
merely
upon
contact,
thereby
simplifying
process.
A
time-resolved
was
developed
utilizing
aflatoxin
B1
(AFB1)
corn,
achieving
limit
(LOD,
IC10)
0.149
ng/mL.
The
accuracy
reliability
Eu-MOFs-LFIA
validated
through
comparisons
spiked
concentrations
during
spiking
blind
sample
analyses,
verification
conducted
using
ultra-high-performance
liquid
chromatography
mass
spectrometry
(UPLC-MS).
Furthermore,
testing
real
samples
demonstrated
that
can
effectively
facilitate
AFB1
corn.
Analysis & Sensing,
Journal Year:
2024,
Volume and Issue:
4(5)
Published: May 17, 2024
Abstract
Electrochemical
immunosensors
have
emerged
in
the
last
years
as
outstanding
analytical
systems
for
detection
of
analytes
clinical
interest.
As
alternative
to
traditional
enzymatic
labels,
use
nanoparticles
and
especially
bimetallic
ones
has
gained
increased
attention
thanks
their
advantages
related
higher
simplicity,
stability
sensitivity
offered.
Main
routes
such
nanoparticle
labels
are
based
on
i)
dissolution
into
corresponding
metal
ions
followed
by
voltammetric
detection;
ii)
taking
advantage
electrocatalytic
effect
metals
towards
secondary
reactions;
iii)
electrochemiluminescence
properties.
