Design and Development of a Non-Enzymatic Electrochemical Biosensor for the Detection of Glutathione

Glutathione (GSH-reduced form) is a tripeptide that plays a vital role as an antioxidant to remove xenobiotics in the human body and changes in GSH levels are a marker for the progression of various diseases. In this context, a highly sensitive non-enzymatic electrochemical biosensor for the detection of GSH has been developed using reduced graphene oxide Manganese oxide (rGMnO) nanocomposite as the nano-interface. Initially, graphene oxide was synthesized by Hummer's method and then thermally reduced in the presence of MnO₂ in a blast furnace to obtain rGMnO nanocomposite. The nanocomposite was characterized to validate its structure and morphological properties via Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and amperometry studies showed that upon the addition of GSH, the Pt/rGMnO modified working electrode exhibited a linear response in the range of 1–100 μM at an input voltage of −0.62 V. The developed sensor was found to have a sensitivity of 0.3256 μA μM⁻¹ and LOD of 970 nM with a recovery of 92–104 % in real blood serum samples.