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 (Ab(1)). The Fe3O4 nano-particles were effectively coupled with the secondary anti-CEA antibody (Ab(2)) and utilized as an electroactive non-enzymatic probe for the catalysis of H2O2. Under optimal conditions, the prepared immunosensor demon-strated promising results and exhibited a wide linear response ranging from 0.005 ng/mL to 4.0 ng/mL, with detection limit of 1.9 pg/mL. The immunosensor's practical application has been confirmed by validation using reference method, demonstrating its efficacy in clinical monitoring of CEA levels in human serum samples. The immunosensor exhibited excellent selectivity and stability.