Epithelial sodium channels (ENaC) is a protein that plays a role in maintaining sodium levels and can be used as a biomarker of hypertension. This study aims to develop an electrochemical immunosensor for detecting ENaC using a screen-printed carbon electrode (SPCE) which is modified with reduced graphene oxide (RGO). The performance of RGO enhanced to provide covalent bonds between the -COOH residues at RGO and the terminal -NH2 of anti-ENaC. While anti-ENaC and ENaC decrease the peak of ferric cyanides current because of the resistance effect. The optimum concentration of anti-ENaC was 1.0 µg/mL for 30 min incubation time. The various concentration of ENaC has a linear relationship with the decreasing of ferric cyanide peak current in the range of 0.01-1.5 ng/mL, and the limit of detection found at 0.198 ng/mL. The low-level exposure of ENaC warrants the realization of a point-of-care device for early detection of hypertension in urine samples.