An ultrasensitive cathodic electrochemiluminescence immunoassay was developed by designing atomically Fe-anchored MOF-on-MOF nanozymes (CoNi-MOF@PCN-224/Fe) as ECL electrode materials and plasmonic Ag/AuNCs as high-efficient co-reactant quenchers. The proposed differential signal amplification strategy endowed the immunoassay with superior detection ability, which provide more possibilities for the ultrasensitive detection of disease markers in clinical diagnosis.
Abstract:
The successful application of electrochemiluminescence (ECL) in immunoassays for clinical diagnosis requires stable electrodes and high-efficient ECL signal amplification strategies. Herein, the authors discovered a new class of atomically dispersed peroxidase-like nanozymes with multiple active sites (CoNi-MOF@PCN-224/Fe), which significantly improved the catalytic performance and uncovered the underlying mechanism. Experimental studies and theoretical calculation results revealed that the nanozyme introduced a Fenton-like reaction into the catalytic system and the crucial synergistic effects of definite active moieties endow CoNi-MOF@PCN-224/Fe strong electron-withdrawing effect and low thermodynamic activation energy toward H2O2. Benefiting from the high peroxidase-like activity of the hybrid system, the resultant ECL electrode exhibited superior catalytic activity in the luminol-H2O2 system and resulted in an ≈17-fold increase in the ECL intensity. In addition, plasmonic Ag/Au core-satellite nanocubes (Ag/AuNCs) were designed as high-efficient co-reactant quenchers to improve the performance of the ECL immunoassay. On the basis of the differential signal amplification strategy (DSAS) proposed, the immunoassay displayed superior detection ability, with a low limit of detection (LOD) of 0.13 pg mL−1 for prostate-specific antigen (PSA). The designed atomically anchored MOF-on-MOF nanozyme and DSAS strategy provides more possibilities for the ultrasensitive detection of disease markers in clinical diagnosis.
Author list:
Chuanping Li*, Tianxiang Hang, Yongdong Jin*
How to cite:
C. Li, T. Hang, Y. Jin, Exploration 2023, 3, 20220151.
https://doi.org/10.1002/EXP.20220151