A novel electrochemical immunosensor based on MWCNT/CuO nanocomposite for effectively detection of carcinoembryonic antigen (CEA)

This study presents the design of a novel electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA). The immunosensor utilizes a glassy carbon electrode (GCE) that is modified with a nanocomposite consisting of copper oxide (CuO) nanoparticles decorated on multi-walled carbon nanotubes (MWCNTs). The detection of CEA is achieved through a sandwich-type assay. Carboxyl groups were introduced onto the surface of the MWCNTs in order to enhance the immobilization of primary anti-CEA antibody (Ab1). The Fe3O4 nanoparticles were effectively coupled with the secondary anti-CEA antibody (Ab2) and utilized as an electroactive non-enzymatic probe for the catalysis of H2O2. Under optimal conditions, the prepared immunosensor demonstrated promising results and exhibited a wide linear response ranging from 0.005 ng/mL to 4.0 ng/mL, with a detection limit of 1.9 pg/mL. The immunosensor's practical application has been confirmed by validation using a reference method, demonstrating its efficacy in clinical monitoring of CEA levels in human serum samples. The immunosensor exhibited excellent selectivity and stability.