Electrochemical immunosensor for detection of CA 15-3 biomarker in point-of-care

• Main Author: Rebelo, Tânia S.C.R.
• Publication Date: 2021
• Other Authors: Ribeiro, José A., Sales, M. Goreti F., Pereira, Carlos M.
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: https://hdl.handle.net/10316/95606; https://doi.org/10.1016/j.sbsr.2021.100445
• topic: CA 15-3; Cancer biomarker; Electrochemical biosensor; Immunosensor; Screen-printed electrode (SPE); Point-of-care (PoC) analysis

This work reports the development of a simple and rapid electrochemical immunosensor for the determination of breast cancer biomarker Cancer Antigen 15–3 (CA 15–3). Disposable and cost-effective chips, consisting of gold screen-printed electrodes (AuSPEs), were used to develop the portable electrochemical devices for monitoring the biomarker in point-of-care (PoC), under clinical context. The biosensor preparation consisted of two simple steps. First, a self-assembled monolayer (SAM) of mer-captosuccinic acid (MSA) was formed at the AuSPE surface. Then, the CA 15–3 antibody was covalently bound to the carboxylic groups standing at the electrode surface using EDC/NHS chemistry. The performance of the developed immunosensor was evaluated by assessing the sensor sensitivity, linear response interval, selectivity and detection limit (LOD). The developed immunosensor provided a wide linear concentration range (from 1.0 to 1000 U mL