A Functionalized Screen-Printed Carbon with CeO 2 /AuNP-Streptavidin-Biotinylated Aptamer as an Electrochemical Biosensor for Detection of Epithelial Sodium Channel (ENaC)

Epithelial sodium channel proteins (ENaC) are highly Na+ selective channels expressed in epithelia which are independently capable of producing sustained severe hypertension. ENaC expression is proportional to sodium intake and is clinically associated with hypertension. The higher the sodium concentration, the higher the amount of ENaC protein in the cell. Electrochemical aptasensors are highly sensitive, robust, and providing a rapid response to a variety of targets, as well as having the potential for miniaturization. This study developed an aptasensor for the detection of ENaC as a biomarker of hypertension via a gold nanoparticle (AuNP)-Aptamer bioconjugate formation that was attached to a screen-printed carbon electrode modified with cerium oxide. The concentration of ENaC was monitored using differential pulse voltammetry of [Fe(CN)6]4−/3- redox system. The limit of detection of ENaC protein with this aptasensor was obtained of 0.110 ng mL-1, in the linear range of concentrations 0.05–3.0 ng mL-1. The developed aptasensor is simple and can be miniaturized to determine the ENaC concentration in urine for the realization of a point-of-care device for the early detection of hypertension.