Electrochemically tracking interactions between molecular ions of sodium dodecyl sulphate and the selected amino acid at the electrode-electrolyte interface

Surfactant assisted electrode-electrolyte (E-E) interface is a fascinating research topic that has been employed in different fields such as biosensing, energy devices, surface technology, etc. This work explores the electrochemical properties of sodium dodecyl sulphate (SDS) in the presence of essential amino acid (AA) i.e., L-Threonine (THR), DL-Methionine (MET), and L-Phenylalanine (PHE) at the E-E inter-face through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). For the electro-chemical study of SDS at its premicellar and post micellar concentration in presence of AA ions, the three -electrode configuration consisting of glassy carbon (GC) as the working electrode, Ag/AgCl as reference electrode, and Pt wire as the counter electrode, have been used. Briton Robinson buffer (pH, 2) was uti-lized as the supporting electrolyte. The effect of AA ions on faradic properties of electroactive ions in the SDS system was studied by CV measurement. The scan rate effect was used to calculate the kinetic parameters such as maximum surface adsorbed concentration (U, mol/cm(2)), diffusion coefficient (D, cm(2)/s), and capacitance of electrode surface (C, F/cm(2)). EIS measurements were applied to study the capacitive and resistive properties of the electric double layer (EDL) that developed at the E-E interface. The double-layer capacitance (Cdl) of EDL was extracted from the equivalent circuit diagram. The results from electrochemical measurements suggested that the electrochemical properties of SDS such as the far-adaic process of electroactive ions and their kinetics through the SDS channel and charge storage performance of electrified surface were strongly affected by AA ions at the E-E interface through electrostatic interactions between oppositely charged ions. This work contributed to the understanding of the electro-chemical interaction of biomolecular ions at the surfactant-assisted E-E interface. It will diversify the application of surface-active agents in biology and biotechnology. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the electrochemical properties of sodium dodecyl sulphate (SDS) in the presence of essential amino acid (AA) ions at the electrode-electrolyte (E-E) interface using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that AA ions strongly affect the electrochemical properties of SDS, including the faradaic process of electroactive ions, their kinetics, and the charge storage performance of the electrified surface. This study contributes to the understanding of the electrochemical interaction of biomolecular ions at the surfactant-assisted E-E interface.