title: Non-Faradaic electrochemical impedance spectroscopy as a reliable and facile method: Determination of the potassium ion concentration using a guanine rich aptasensor.
abstract: In this article we report the application of non-Faradaic mode of electrochemical impedance spectroscopy (EIS) for determination of potassium ion (K(+)) concentration using a guanine rich K(+)-selective aptasensor (K(+)-aptasensor). This is a simple, electroactive probe free, sensitive and reproducible method allowing determination of K(+) ion concentration without any disturbance from electroactive probes used in similar works based on the Faradaic EIS method. Herein, a wide linear range of K(+) ion concentrations (1 μM-0.1mM) with a 200 nM limit of detection was achieved which is better than most of the previously reported Faradaic biosensing methods. The proposed method maintains valuable applications when it is used for K(+) determination in the presence of potentially important interferences in biological media. Thus, application of the non-Faradaic EIS method for sensing the concentration of K(+) ion with the presented K(+)-aptasensor can find an important role in clinical assay.
authors.affiliation: Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran. Electronic address: habibkazemi@iasbs.ac.ir.
authors.forename: Sayed Habib
authors.initials: SH
authors.lastname: Kazemi
authors.affiliation: Analytical Chemistry Research group, Research Institute of Petroleum Industry (RIPI), Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Shanehsaz
authors.affiliation: Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Ghaemmaghami
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D004563:Electrochemistry / Q000379:methods*; D006147:Guanine / Q000737:chemistry; D011188:Potassium / Q000737:chemistry*
chemical_list: D006147:Guanine; D011188:Potassium
keywords: Aptamer; Aptasensor; Biosensor; Impedance