Development of a method for the determination of glutathione reductase enzyme from spinach by square wave cathodic stripping voltametry

In this study, a new electrochemical method was developed to calculate the activity of glutathione reductase enzyme (GR) using the square wave cathodic stripping voltammetry method. The effects of different parameters such as enzyme concentration, pH, deposition time and deposition potential on reduced glutathione (GSH) peak were investigated using the square wave cathodic stripping voltammetry method. The sample used to determine the GR enzyme was isolated from spinach. The activity of GR enzyme isolated from spinach was calculated in Unit/mL by square wave cathodic stripping voltammetry. The enzymatic activity of GR obtained by this method was compared with the results obtained using UV-GB spectroscopy and the results showed that the new method was reliable. Observation and detection limit values for GSH were calculated and CLOD= 4.14×10-7 M and CLOQ=13.8×10-7 M. In addition, some electrochemical behaviors of GSH were investigated. As a result, it has been determined that the boundary current is 1.962×10-9 A, the cottrell slope is 2,499×10-7, the diffusion coefficient is 1.849×10-5 cm2/s, the number of electrons transferred per mole during reduction is 2, diffusion-controlled and the reduction mechanism is the 'ECE mechanism'.