Electrocatalytic Determination of Glutathione Using Multiwall Carbon Nanotubes Paste Electrode as a Sensor and Isoprenaline as a Mediator

In this study, we propose isoprenaline (ISPT) as a new mediator for the rapid, sensitive, and highly selective voltammetric determination of glutathione (GSH) using multiwall carbon nanotubes paste electrode (MWCNTPE). It has been shown by direct current cyclic voltammetry, double step chronoamperometry and electrochemical impedance spectroscopy (EIS) that this modified electrode can catalyze the oxidation of GSH in aqueous solution. The kinetic parameters of the system including electron transfer coefficient, and catalytic rate constant were also determined using the electrochemical approaches. In addition, linear sweep voltammetry (LSV) was used for quantitative analysis. LSV showed wide linear dynamic range (0.5 – 300.0 μM GSH) with a detection limit of 0.09 μM GSH. Finally, this method was also examined as a selective, simple and precise electrochemical sensor for the determination of GSH in real samples such as hemolysed erythrocyte, tablet and urine.