In this study, an electrochemical biosensor for determination of Carcinoembryonic antigen (CEA) biomarker using human breast ductal adenocarcinoma (MCF-7) and human ovarian adenocarcinoma (SK-OV-3) cancer cells was presented. Disposable pencil graphite electrodes (PGE) has been modified with Au nanoparticle (Au NP) and MoS2 nanostructure dispersed chitosan (Cs) matrix. Therefore, the electrochemical interaction between the antibody-electrode surface was facilitated. Under optimal conditions, the immunosensor exhibited high sensitivity toward CEA biomarker in the low concentration range 0.01-10 ng mL(-1), with the detection limit of 1.93 ng mL(-1) and relative standard deviation of 4.65 (n = 5). The results indicated that even very small changes in CEA concentration can be sensed with the presented system. Also, recovery of the immunosensor found as 98 +/- 3% in the real sera samples containing dopamine and ascorbic acid. It has a great potential in the clinical screening of divergent cancer biomarkers. Experiments were conducted to determine the number of normal cell hGF and cancer cells adhered and attached on immuno-cytosensor surfaces. CEA-positive MCF-7 cells have shown great potential for adhesion and attachment to MoS2/Cs/Au/Anti-CEA/CEA surface better than CEA-negative cells. The developed immuno-cytosensor exhibited very promising results for the future biosensor studies.