A sandwich-type electrochemical immunosensor based on Au-rGO composite for CA15-3 tumor marker detection

Author(s)

Martins, Thiago S. ^[1] ; Bott-Neto, Jose L. ^[2] ; Oliveira, Jr., Osvaldo N. ^[2] ; Machado, Sergio A. S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Microchimica Acta; v. 189, n. 1 JAN 2022.
• Web of Science Citations: 0

Abstract

A sensitive detection of carbohydrate antigen 15-3 (CA15-3) levels may allow for early diagnosis and monitoring the treatment of breast cancer, but this can only be made in routine clinical practice if low-cost immunosensors are available. In this work, we developed a sandwich-type electrochemical immunosensor capable of rapid detection of CA15-3 with an ultra-low limit of detection (LOD) of 0.08 fg mL(-1) within a wide linear concentration range from 0.1 fg mL(-1) to 1 mu g mL(-1). The immunosensor had a matrix of a layer-by-layer film of Au nanoparticles and reduced graphene oxide (Au-rGO) co-electrodeposited on screen-printed carbon electrodes (SPCE). The high sensitivity was achieved by using secondary antibodies (Ab(2)) labeled with horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2) as signal amplifiers, and hydroquinone (HQ) was used as an electron mediator. The immunosensor was selective for CA15-3 in human serum and artificial saliva samples, robust, and stable to permit storage at 4 degrees C for more than 30 days. With its high performance, the immunosensor may be incorporated into future point-of-care (POC) devices to determine CA15-3 in distinct biological fluids, including in blood and saliva samples. (AU)

• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/13514-9 - Electrochemical sensors with a matrix containing graphene quantum dots or nanoribbons for the detection of biomarkers
• Grantee: Jose Luiz Bott Neto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/01777-5 - Manufacture of disposable electrochemical devices composed of hollow carbon nanospheres and carbon nanowires decorated with silver nanoparticles for the quantification of endocrine disruptors in supply water samples
• Grantee: Sergio Antonio Spinola Machado
• Support Opportunities: Regular Research Grants