Electrochemical Oxidation of Glutathione in the Presence of Tryptophan at Carbon Paste Electrode Modified with Ni-Zn-Metal-Organic Frameworks/Graphene Oxide and Ferrocene Derivative

Glutathione (GSH) plays a vital physiological role as it is implicated in the progression and pathogenesis of a wide range of medical conditions, including diabetes, various types of cancer, and Parkinson’s disease. Due to the fundamental physiological importance of GSHand its relevance to numerous medical conditions, there is a clear need to develop simple, rapid, and cost-effective analytical methods. These methods could significantly aid in clinical diagnostics and guide the optimization of treatment approaches. This work reports the synthesis and characterization of a Ni-Zn-metal-organic framework/graphene oxide (Ni-Zn-MOF/GO) composite material, and its application as a modifier for a carbon paste electrode (CPE) in the electrochemical detection of GSH. The Ni-Zn-MOF/GO/ferrocene (FC)-modified CPE (Ni-Zn-MOF/GO/FC/CPE) was developed for this purpose. The Ni-Zn-MOF/GO/FC/CPE electrochemical sensor exhibited two linear response ranges for GSH: from 0.01–90.0 μM, and from 90.0–800.0 μM, with a detection limit estimated to be 0.003 μM. Importantly, Ni-Zn-MOF/GO/FC/CPE was shown to be suitable for the determination of GSH in the presence of tryptophan in real samples, such as human blood, GSH tablet and urine samples. The results highlight the potential of the Ni-Zn-MOF/GO/FC/CPE electrochemical sensor as a reliable and sensitive platform for the detection of GSH.