Combination
of Ternary Electrochemiluminescence System
of BNQDs/AgMOG‑K2S2O8 and
Electrochemiluminescence Resonance Energy Transfer Strategy for Ultrasensitive
Immunoassay of Amyloid‑β Protein
posted on 2023-12-15, 20:03authored byMengting Sheng, Linying Yu, Yao Peng, Qian Wang, Jianshe Huang, Xiurong Yang
In
this work, based on boron nitride quantum dots (BNQDs)
as energy
donors and MnO2@MWCNTs-COOH as energy receptors, we designed
an efficient electrochemiluminescence resonance energy transfer (ECL-RET)
immunosensor for the detection of amyloid-β (Aβ42) protein, a biomarker of Alzheimer’s disease (AD). First,
the signal amplification of a ternary ECL system composed of BNQDs
(as the ECL emitter), K2S2O8 (as
the coreactant), and silver metal–organic gels (AgMOG, as the
coreaction accelerator) was realized, and PDDA as stabilizer was added,
a strong and stable initial ECL signal was obtained. AgMOG could not
only support a large amount of BNQDs and Aβ42 capture
antibody (Ab1) through Ag–N bond but also exhibit
excellent ECL catalytic performance and enhance the luminescent intensity
of BNQDs@PDDA-K2S2O8 system. In addition,
due to the broad absorption spectrum of MnO2@MWCNTs-COOH
and the extensive overlap with the ECL emission spectrum of BNQDs,
the quenching probe Ab2-MnO2@MWCNTs-COOH could
be introduced into the ternary system through a sandwich immune response.
On this basis, the signal on–off ECL immunosensor was constructed
to achieve the ultrasensitive detection of Aβ42 through
signal transformation. Under the optimal conditions, the prepared
ECL biosensor manifested a wide linear range (10 fg/mL–100
ng/mL) with a detection limit of 2.89 fg/mL and showed excellent stability,
selectivity, and repeatability, which provided an effective strategy
for the ultrasensitive detection of biomarkers in clinical analysis.