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A theoretical and experimental study of polyaniline/GCE and DNA G-quadruplex conformation as an impedimetric biosensor for the determination of potassium ion

P. Salehan, Ali A. Ensafi,  K. Zarean Mousaabadi,  Jahan B. Ghasemi, E. Aghaee, B. Rezaei

Chemosphere,Volume 292April 2022, 133460, https://www.sciencedirect.com/science/article/abs/pii/S0045653521039345

Abstract

An electrochemical aptasensor has been developed to determine K+ using electrochemical impedance spectroscopy. The polyaniline (PANI) coating was first electrodeposited on a GCE. Then, the potassium-selective aptamer [G3(T2AG3)3] was adsorbed through an electrostatic force between PANI and aptamer. In the presence of K+, the single-stranded DNA is folded into the G-quadruplex configuration, which acts as a barrier against electron transfer at the GCE surface. AFM and FE-SEM images characterize the surface morphology at each fabrication stage. As the K+ concentration increased, the charge transfer resistance (Rct) increased, and the plot of ΔRct versus the logarithm of the K+ concentration is linear over a wide range of 10 pM–60 μM with a low detection limit of 3.7 pM. Finally, the proposed sensor was used to determine K+ in water, serum, urine, and fruit samples. Moreover, the binding stability of the aptamer/PANI and K+/Aptamer/PANI and the interactions between the aptamer and PANI were analyzed through molecular dynamics simulation.

 

Keywords: Potassium ion Biosensor Polyaniline Aptamer Electrochemical impedance spectroscopy Molecular dynamics simulation

Journal Papers
Month/Season: 
April
Year: 
2022

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