Herein, we report the biocompatible amine-functionalized gadolinium oxide nanoparticles (Gd2O3NPs) for the possibility of electrochemical detection ofVibrio cholerae(Vc) cells. The microwave irradiation process is applied to synthesize Gd2O3NPs. The amine (NH2) functionalization is carried out via overnight stirring with 3(Aminopropyl)triethoxysilane (APTES) at 55 °C. The size of NPs amine functionalized APETS@Gd2O3NPs are determined by transmission electron microscopy (TEM). APETS@Gd2O3NPs are further electrophoretically deposited onto indium tin oxide (ITO) coated glass substrate to obtain working electrode surface. The monoclonal antibodies (anti-CT) specific to cholera toxin associated toVccells are covalently immobilized onto the above electrodes using EDC-NHS chemistry and further BSA is added to obtain the BSA/anti-CT/APETS@Gd2O3/ITO immunoelectrode. Further, this immunoelectrode shows the response for cells in CFU range from 3.125 × 106to 30 × 106and is very selective with sensitivity and LOD 5.07 mA CFUs mL cm−2and 0.9375 × 106CFU respectively. To establish a future potential for APTES@Gd2O3NPs in field of biomedical applications and cytosensing, the effect of APTES@Gd2O3NPs on mammalian cells is also observed using in vitro cytotoxicity assay and cell cycle analysis.