Issue 40, 2018

Facile and feasible conductometric immunoanalytical assay for alpha-fetoprotein using platinum-functionalized graphitic carbon nitride nanosheets

Abstract

A simple and feasible conductometric immunoanalytical method was developed for the sensitive detection of a liver cancer biomarker (alpha-fetoprotein, AFP) on an interdigitated comb-like transducer, using platinum (Pt)-functionalized graphitic carbon nitride (g-C3N4) nanosheets. To construct such an immunosensing platform, platinum nanoparticles were initially loaded on the g-C3N4 nanosheets by the aid of a ethylene glycol reduction method. Thereafter, the as-prepared Pt–g-C3N4 nanohybrids were used as the affinity support for the immobilization of anti-AFP antibodies on the interdigitated electrode. Upon addition of AFP, the analyte reacted with the immobilized antibody to form the antigen–antibody immunocomplex, which was coated on the surface of the modified electrode, thereby partly decreasing the electrocatalytic efficiency of Pt–g-C3N4 towards the reduction of hydrogen peroxide (H2O2) in the presence of iodine ions (I). The variation in the local conductivity by iodine ions could be detected by using an external conductometer on the basis of the Pt–g-C3N4 electrocatalytic reaction in 10 mM phosphate buffer (pH 6.5) containing 80 μM H2O2, 50 mM KI and 0.1 M NaCl. Under optimum conditions, the immunosensor exhibited good conductometric responses for the detection of AFP within the dynamic linear range of 0.1–100 ng mL−1 at a detection limit of 0.097 ng mL−1. The strong attachment of anti-AFP antibodies to the Pt–g-C3N4 brought good repeatability and intermediate precision down to ±12.7%. Importantly, no significant differences at the 0.05 significance level were encountered for the analysis of 12 human serum samples between the developed immunoassay and human AFP ELISA kit for AFP determination.

Graphical abstract: Facile and feasible conductometric immunoanalytical assay for alpha-fetoprotein using platinum-functionalized graphitic carbon nitride nanosheets

Article information

Article type
Paper
Submitted
12 août 2018
Accepted
19 sept. 2018
First published
20 sept. 2018

Anal. Methods, 2018,10, 4886-4893

Facile and feasible conductometric immunoanalytical assay for alpha-fetoprotein using platinum-functionalized graphitic carbon nitride nanosheets

L. Li, W. Guo, Y. Lin, D. Tang and J. Liu, Anal. Methods, 2018, 10, 4886 DOI: 10.1039/C8AY01789A

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