Issue 21, 2018

A novel electrochemical immunoassay for carcinoembryonic antigen based on glucose oxidase-encapsulated nanogold hollow spheres with a pH meter readout

Abstract

A portable electrochemical immunosensing protocol was designed for the sensitive detection of a disease-related tumor biomarker (carcinoembryonic antigen, CEA, used in this case) on a pH meter using glucose oxidase (GOx)-encapsulated gold hollow microspheres (AuHMs) for signal amplification. The assay was carried out on a monoclonal anti-CEA capture antibody-coated microplate with a sandwich-type reaction mode. The GOx-entrapped AuHM was first synthesized using the reverse micelle method and then used as the signal-generation tag for the labeling of polyclonal anti-CEA detection antibody. Accompanying the formation of the sandwiched immunocomplexes, the loaded GOx molecules in the microsphere could catalyze glucose into gluconic acid and hydrogen peroxide. The as-produced gluconic acid changed the microenvironment of the detection solution, thus resulting in the shift of the pH value, which could be quantitatively determined on a portable pH meter. The use of gold hollow microspheres was expected to enhance the loaded amount of GOx for signal amplification. Two labeling protocols including GOx-labeled secondary antibody and GOx-AuHM-labeled secondary antibody were investigated for CEA detection, and improved analytical features were acquired with GOx-AuHM labeling. With the GOx-AuHM labeling strategy, the pH meter-based immunosensing device exhibited a good analytical performance for CEA detection within the dynamic linear range of 0.1–100 ng mL−1 at a detection limit of 0.062 ng mL−1. The strong attachment of anti-CEA antibodies to GOx-AuHM brought a good repeatability and intermediate precision down to 10%. Importantly, no significant differences at the 0.05 significance level were encountered in the analysis of 12 human serum specimens between the developed immunoassay and the commercialized electrochemiluminescent method for CEA determination.

Graphical abstract: A novel electrochemical immunoassay for carcinoembryonic antigen based on glucose oxidase-encapsulated nanogold hollow spheres with a pH meter readout

Article information

Article type
Paper
Submitted
29 Jūl. 2018
Accepted
10 Sept. 2018
First published
13 Sept. 2018

Analyst, 2018,143, 5271-5277

A novel electrochemical immunoassay for carcinoembryonic antigen based on glucose oxidase-encapsulated nanogold hollow spheres with a pH meter readout

Y. Jiang, Z. Su, J. Zhang, M. Cai and L. Wu, Analyst, 2018, 143, 5271 DOI: 10.1039/C8AN01436A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements