Gold-Loaded Nanoporous Ferric Oxide Nanocubes with Peroxidase-Mimicking Activity for Electrocatalytic and Colorimetric Detection of Autoantibody
Embargoed until: 2018-09-01
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Enzyme-mimicking activity of iron oxide based nanostructures have provided a significant advantage in developing advanced molecular sensors for biomedical and environmental applications. Herein, we introduce the horseradish peroxidase (HRP)-like activity of gold loaded nanoporous ferric oxide nanocubes (Au-NPFe2O3NC) for the development of a molecular sensor with enhanced electrocatalytic and colorimetric (naked-eye) detection of autoantibodies. The results showed that Au-NPFe2O3NC exhibits enhanced peroxidase-like activity towards the catalytic oxidation of 3,3ˊ,5,5ˊ-tertamethylbenzidine (TMB) in the presence of H2O2 at room temperature (25°C) and follows the typical Michaelis–Menten kinetics. The autoantibody sensor based on this intrinsic property of Au-NPFe2O3NC resulted excellent detection sensitivity (LOD = 0.08 U/mL) and reproducibility (% RSD = < 5% for n = 3) for analysing p53-specific autoantibodies using electrochemical and colorimetric (naked-eye) readouts. The clinical applicability of the sensor has been tested in detecting p53-specific autoantibody in plasma obtained from patients with epithelial ovarian cancer high-grade serous subtype (EOCHGS, number of samples = 2) and controls (benign, number of samples = 2). As Au-NPFe2O3NC possess high peroxidase-like activity for the oxidation of TMB in the presence of H2O2 (TMB is a common chromogenic substrate for HRP in ELISAs), we envisage that our assay could find a wide range of application in developing ELISA based sensing approaches in the field of medicine (i.e. detection of other biomarkers same as p53 autoantibody), biotechnology and environmental sciences.
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright 2017 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see 10.1021/acs.analchem.7b02880.
This publication has been entered into Griffith Research Online as an Advanced Online Version.
Analytical Chemistry not elsewhere classified