Simple and Label-Free Electrochemical Immuno Determination of the Gastric Cancer Biomarker Carbohydrate Antigen 72-4 with a Carbon Nanotube-Graphene Oxide Hybrid as the Sensing Platform and Ferrocyanide/Ferricyanide as the Probe

Abstract

Developing simple and effective method for carbohydrate antigen 72-4 (CA72-4) detection is important to achieve the early diagnosis and treat of gastric cancer. In this work, multiwalled carbon nanotubes (MWCNT) were treated with a simple wet-chemistry method to form MWCNT/graphene oxide (MWCNT/GO) core/shell nanohybrids that provide high electron transfer, high dispersibility, and a large surface area to immobilize CA72-4 antibodies (Ab) due to the carboxyl groups on the GO shell. Using ferrocyanide/ferricyanide ([Fe(CN)₆]^3−/4−) as the signaling probe, a simple, label-free and effective electrochemical immunosensing platform was constructed for CA72-4. Upon optimizing the experimental conditions, the simple MWCNT/GO hybrids-based immunosensor showed desirable sensing including a wide linear range and low detection limit. Furthermore, the reproducibility, selectivity and practical applications demonstrated potential value to determine CA72-4 in clinical applications for diagnosing gastric cancer.

Keywords:

• Carbohydrate antigen 72-4
• differential pulse voltammetry (DPV)
• electrochemical sensing
• gastric cancer
• immunosensor

Additional information

Funding

The work was supported by Fujian Provincial Health Technology Project (Grant number 2017-ZQN-18) and the Fujian Science and Technology Program (Grant number 2019J05139, 2019J01052065).