Electrochemical immunosensor for the breast cancer marker CA 15–3 based on the catalytic activity of a CuS/reduced graphene oxide nanocomposite towards the electrooxidation of catechol

• Published in: Mikrochimica acta (1966) Vol. 185; no. 1; pp. 79 - 9
• Main Authors: Amani, Jafar, Khoshroo, Alireza, Rahimi-Nasrabadi, Mehdi
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.01.2018; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Breast cancer; Carbohydrates; Catalysis; Catalytic activity; Catechin; Catechol; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Copper sulfides; Electrochemical reactions; Electrodes; Enzyme-linked immunosorbent assay; Graphene; Immunosensors; Microengineering; Nanochemistry; Nanocomposites; Nanotechnology; Original Paper; Oxidation; Reproducibility; Sulfides; Biosensor; Copper sulfide; Screen-printed electrode; Electrochemistry; Immunosensors; Carbohydrate antigen 15–3; Tumor biomarkers
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-017-2532-5

The authors report on an electrochemical immunosensor for the tumor marker carbohydrate antigen 15–3 (CA15–3). It is based on the use of a composite consisting of reduced graphene oxide (RGO) and copper sulfide (CuS) that was placed on a screen-printed graphite electrode. The electrode shows excellent activity towards the oxidation of catechol acting as an electrochemical probe, best at a working potential of 0.16 V. The electrode was modified with antibody against CA15–3. Once the analyte (CA15–3) binds to the surface of the electrode, the response to catechol is reduced. The assay has a linear response in the 1.0–150 U mL −1 CA15–3 concentration range, with a 0.3 U mL −1 lower detection limit and a sensitivity of 1.88 μA μM −1  cm −2 . The immunosensor also shows good reproducibility (2.7%), stability (95% of the initial values after storing for four weeks). The method was successfully applied to the determination of CA15–3 in serum samples, and results were found to compare well to those obtained by an ELISA. Conceivably, this nanocomposite based detection scheme has a wider scope and may be applied to numerous other immunoassays. Graphical abstract A label-free electrochemical immunosensor based on copper sulfides/graphene nanocomposites was developed for enzyme-free determination of CA15–3 biomarker. This immunosensor can be utilized as a tool to detect of CA15–3 in real samples.