An aptasensor using ceria electrodeposited-screen-printed carbon electrode for detection of epithelial sodium channel protein as a hypertension biomarker

Abstract

Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintaining the levels of sodium in blood plasma. A person with a family history of hypertension has a high enough amount of ENaC protein in the kidneys or other organs, so that the ENaC protein acts as a marker that a person is susceptible to hypertension. An aptasensor involves aptamers, which are oligonucleotides that function similar to antibodies, as sensing elements. An electrochemical aptasensor for the detection of ENaC was developed using a screen-printed carbon electrode (SPCE) which was modified by electrodeposition of cerium oxide (CeO 2 ). The aptamer immobilization was via the streptavidin–biotin system. The measurement of changes in current of the active redox [Fe(CN) 6 ] 3−/4− was carried out by differential pulse voltammetry. The surfaces of SPCE and SPCE/CeO 2 were characterized using scanning electron microscopy, voltammetry and electrochemical impedance spectroscopy. The Box–Behnken experimental optimization design revealed the streptavidin incubation time, aptamer incubation time and streptavidin concentrations were 30 min, 30 min and 10.8 µg ml −1 , respectively. Various concentrations of ENaC were used to obtain the linearity range of 0.05–3.0 ng ml −1 , and the limits of detection and quantification were 0.012 ng ml −1 and 0.038 ng ml −1 , respectively. This aptasensor method has the potential to measure the ENaC protein levels in urine samples as well as to be a point-of-care device.

Synthesis and characterization of nanoceria for electrochemical sensing applications

“…Their high isoelectric point, adsorption capacity, mechanical strength, non-toxicity, and good biocompatibility, enable them to adapt to the requirements for sensors employed with biological matrices. 87 Nanoceria is an ideal material to immobilize negatively charged biomolecules, due to its isoelectric point, e.g. , 9.2.…”

Screen-printed electrode-based biosensors modified with functional nucleic acid probes and their applications in this pandemic age: a review

“…2C, Bahti et al developed an SPCE that was modified by the electrodeposition of cerium oxide (CeO 2 ). 49 This kind of nanoceria has properties of oxygen transfer capability, switchable redox reactivity, large surface area, variations in shape, size, charge, surface reactivity, surface coating, and a rigid framework, making CeO 2 very suitable for powerful candidates in the modification of the electrode. 50,51 Moreover, mesoporous-hollow CeO 2 nanospheres showed a strong interaction with –NH 2 to anchor streptavidin and thionine for the immobilization of aptamers onto the electrode surface.…”

Nanostructured Ceria: Biomolecular Templates and (Bio)applications

“…Sensors were developed to monitor the presence of drugs, such as sulfonamide [173] and omeprazole [174]. Additional targets were a hypertension biomarker consisting of the epithelial sodium channel [175], and TNF-alpha for the early screening of neonatal diseases [176]. Ceria NPs were combined with iron oxide for the binding of carboxylic acid groups of a specific antibody that recognizes the carbohydrate antigen 19-9 as a cancer marker.…”