Gold-Loaded Nanoporous Ferric Oxide Nanocubes with Peroxidase-Mimicking Activity for Electrocatalytic and Colorimetric Detection of Autoantibody

Anal Chem. 2017 Oct 17;89(20):11005-11013. doi: 10.1021/acs.analchem.7b02880. Epub 2017 Sep 26.


The enzyme-mimicking activity of iron oxide based nanostructures has 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 toward the catalytic oxidation of 3,3',5,5'-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 in excellent detection sensitivity [limit of detection (LOD) = 0.08 U/mL] and reproducibility [percent relative standard deviation (% RSD) = <5% for n = 3] for analyzing 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 enzyme-linked immunosorbent assays (ELISAs)], we envisage that our assay could find a wide range of application in developing ELISA-based sensing approaches in the fields of medicine (i.e., detection of other biomarkers the same as p53 autoantibody), biotechnology, and environmental sciences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoantibodies / analysis
  • Autoantibodies / blood*
  • Biocompatible Materials / chemistry*
  • Biocompatible Materials / metabolism
  • Catalysis
  • Colorimetry / methods*
  • Electrochemical Techniques
  • Female
  • Ferric Compounds / chemistry*
  • Gold / chemistry*
  • Humans
  • Hydrogen Peroxide / chemistry
  • Kinetics
  • Limit of Detection
  • Nanopores
  • Nanostructures / chemistry*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Oxidation-Reduction
  • Peroxidases / metabolism
  • Reproducibility of Results
  • Tumor Suppressor Protein p53 / immunology


  • Autoantibodies
  • Biocompatible Materials
  • Ferric Compounds
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • ferric oxide
  • Gold
  • Hydrogen Peroxide
  • Peroxidases