A
designed
"on-off-on"
signal-switchable
electrochemiluminescence
(ECL)
aptasensor
based
on
a
donor-acceptor
(D-A)
conjugated
covalent
triazine
framework
(CTF)
has
been
constructed
for
the
sensitive
and
accurate
detection
of
aflatoxin
B1
(AFB1)
with
assistance
nicking
endonuclease
(Nb.BbvCI)-powered
DNA
walking
machine.
The
D-A
CTF,
generated
from
reaction
between
2,4,6-tris(4-formylphenyl)-1,3,5-triazine
(TFPT)
tris(4-aminophenyl)methane
(TAPM)
(denoted
as
TFPT-TAPM-CTF),
simultaneously
serves
superior
ECL
emitter
platform
anchoring
bioprobe.
high
response
TFPT-TAPM-CTF
can
be
quenched
by
anchored
Cy5-labeled
single-strand
(Cy5-ssDNA)
via
resonance
energy
transfer.
Furthermore,
immobilization
double-strand
AFB1-targeting
aptamer
walker
(Hp)
reduces
TFPT-TAPM-CTF.
When
detecting
AFB1,
separates
to
capture
specific
targets,
resulting
in
hybridization
free
Hp
strand
Cy5-ssDNA.
With
Nb.BbvCI,
released
partial
Cy5-ssDNA
helps
recover
some
extent,
further
liberating
autonomously
bind
another
trigger
new
cleavage
process.
In
addition
its
selectivity
promising
practicality,
shows
an
ultralow
limit
0.59
pg·mL-1
within
wide
range
1.0
5.0
×
104
pg·mL-1.
This
work
broadens
application
CTF
food
safety
field
provides
aptasensing
strategy
precise
inspection
mycotoxins
products.
