Electrochemical Studies of Inclusion Complex Formed Between Glutathione and β‐cyclodextrin‐modified Carbon Electrodes and its Application for Determination of Glutathione

Abstract

AbstractIn this work, the electrochemical determination of glutathione (GSH) using β‐cyclodextrin (β‐CD) modified carbon electrodes was carried out. Different methodologies were used to modify the electrodes. In the first part of this paper, we analyze and compare the ability of the electrodes to determine GSH using the different β‐CD‐modified electrodes and cyclic voltammetry. We found that the carbon paste electrode modified by potential sweeping was the best electrode for GSH determination; in addition, we found that an inclusion complex formed between β‐CD deposited on the electrode surface and GSH. The formation constant for this complex was 2498.54 M−1 at 25 °C. Furthermore, we have also calculated thermodynamic parameters for the formation of the inclusion complex. In the second part of this paper, we analyze the effect of sweep rate and pH on the determination of GSH. The best results were obtained at a rate of 50 mV s−1 and a pH of 2.2. The β‐CD‐modified carbon paste electrode exhibits a linear response in a concentration range of 20 to 157 µM with a sensitivity of 1083.65 µA mM−1cm−2 and a detection limit of 3.92 µM. Finally, the electrode was used to determine the GSH concentration in Eichhornia crassipes root extract, and the concentration determination accuracy was validated by a well‐known spectroscopic method.