Voltammetric determination of glutathione in pharmaceutical and biological samples using multiwall carbon nanotubes paste electrode in the presence of rutin as a mediator

A new sensitive, selective and nonexpensive electrochemical sensor was developed for electrocatalyticdetermination of glutathione (GSH)in pharmaceutical and biological samples. GSH is a tripeptide thiol present in all eukaryotic and probiotic cells. A voltammetric studyof GSH has been carried out at the surface of carbon paste electrode modified with multiwall carbon nanotubes(MWCNTPE) in the presence of rutin as a mediator. The electrochemical oxidation of GSH was investigatedby cyclic voltammetry, chronoamperometry and square wave voltammetry (SWV) techniques. Under the optimized conditions, the peak current was linear to GSH concentration over the concentration rangeof 0.3 to 180μmol L−1 using SWV. The detection limit was 0.09μmol L−1. The proposed method wassuccessfully applied to the determination of GSH in the urine,tablet and hemolysed erythrocyte samples.