Abstract
Label-free immunoassay is confronted with a great challenge that its insufficient sensitivity for low con-centration analytes,which can be assigned to the low catalytic efficiency of modified materials towards electroactive molecules.Herein,a universal MOF nanozyme-induced catalytic amplification strategy was proposed for constructing highly sensitive label-free electrochemical immunoassay.Specifically,the syn-thesized CuFe-MOF nanozyme with superior peroxidase(POD)-like activity,regarding as a MOF nanozyme model,can catalyze hydrogen peroxide to produce hydroxyl radicals(·OH),which can efficiently oxidize electroactive probe(such as 1,2-phenylenediamine(o-PD))accompanying with intense electrochemical signals.Modification of MOF nanozyme on the electrode and capture of antibodies for binding target antigens hinder the catalytic process of MOF nanozyme toward o-PD,resulting in a gradual decrease in electrochemical signal with increasing target antigen concentration,enabling quantitative label-free immunoassay.Thus,a highly sensitive label-free immunosensor using MOF nanozyme-induced catalytic amplification achieved effective detection of Immunoglobulin G(IgG)with a wide linear range of 0.001-50ng/mL and low detection limit of 0.45 pg/mL.This work proposes a promising nanozyme-induced cat-alytic amplification strategy for the development of label-free electrochemical immunoassay.
维普
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