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Updated: Feb 5, 2026

Development of an Electrochemical DNA Biosensor to Detect a Foodborne Pathogen
Published on: June 3, 2018
A highly sensitive and reliable detection of CA15-3 in patient plasma with electrochemical biosensor labeled with
Sattar Akbari Nakhjavani1, Balal Khalilzadeh2, Parvin Samadi Pakchin3
1Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract:
An early on-time detection of breast cancer can effectively affect the outcome of the treatment. Here, we developed an ultrasensitive, simple and reliable immunosensor to detect the lowest alteration of CA 15-3, the standard biomarker of breast cancer patients. The proposed immunosensor was achieved by modification of gold electrode by streptavidin to immobilize the biotinylated anti-CA 15-3 monoclonal antibody (mAb). Bovine serum albumin was used to prevent nonspecific binding. To improve the sensitivity of modified immunosensor, the sandwich signal enhancer consisting of streptavidin-coated magnetic beads conjugated with biotinylated horseradish peroxidase (HRP) and anti-CA 15-3 biotinylated mAb was applied. The electrochemical measurements were obtained in the presence of hydroquinone as a redox agent and H2O2 as the activating agent of HRP. Under optimized condition and using square wave voltammetry, the lower limit of quantification was obtained as 15 × 10-6 U/mL and the linear CA 15-3 concentration range was 50-15 × 10-6 U/mL. While showing significant stability, the immunosensor displayed an excellent sensitivity and specificity for the detection of CA 15-3 even in the human serum as compared to the enzyme-linked immunosorbent assay (ELISA) as a gold standard method. Based on our findings, the engineered immunosensor is proposed as a robust diagnostic tool for the clinical determination of CA 15-3 and other cancer biomarkers.
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