A Highly Sensitive and Reliable Detection of Ca15-3 in Patient Plasma With Electrochemical Biosensor Labeled With Magnetic Beads Publisher Pubmed



Akbari Nakhjavani S^{1, 2} ; Khalilzadeh B³ ; Samadi Pakchin P^{2, 4} ; Saber R⁴ ; Ghahremani MH^{1, 5} ; Omidi Y^{2, 6, 7}
Source: Biosensors and Bioelectronics Published:2018

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. © 2018 Elsevier B.V.