Preparation, characterization and electrochemical application of Ag-ZnO nanoplates for voltammetric determination of glutathione and tryptophan using modified carbon paste electrode

Ag-ZnO nanoplates and 2-chlorobenzoyl ferrocene were synthesized and used to construct a modified carbon paste electrode. The electrooxidation of glutathione at the surface of the modified electrode was studied. Under the optimized conditions, the square wave voltammetric (SWV) peak current of glutathione increased linearly with glutathione concentrations in the range of 5.0 × 10− 8 to 2.0 × 10− 4 M with sensitivity of 0.659 μA μM− 1 and method detection limit of 20.0 nM was obtained for glutathione. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of glutathione and tryptophan which makes it suitable for the detection of glutathione in the presence of tryptophan in real samples.