Here in, a high sensitive sandwich-type electrochemical immunosensor for the determination of SKBR-3 breast cancer cell has been fabricated using of green synthesized reduced graphene oxide as a platform to the immobilization of primary Herceptin antibody (Anti-HCT). The various reduced graphene oxide-tetrasodium 1, 3, 6, 8-pyrenetetrasulfonic acid/metal hexacyanoferrates (rGO-TPA/MHCF_nano) nanocomposites included rGO-TPA/FeHCF, rGO-TPA/CoHCF, rGO-TPA/NiHCF and rGO-TPA/CuHCF were used as electrochemical labels of secondary Herceptine antibody. The obtained result showed that the sensitivity of proposed sandwich-type electrochemical immunosensor for the determination of SKBR-3 breast cancer cells (30,000 cells mL⁻¹) using rGO-TPA/FeHCF_nano labeled secondary Herceptine antibody was higher than the other rGO-TPA/MHCF_nano-labeled secondary Herceptine antibodies. The differential pulse voltammetry (DPV) technique was used for the determination of SKBR-3 breast cancer cell in the concentration range of 500–30,000 cells mL⁻¹ with the limit of detection of 21 cells mL⁻¹. The proposed sandwich-type electrochemical immunosensor exhibited high selectivity, liner range responsibility and good stability.