Electrochemical Detection of Peroxynitrite Using Selenium-Decorated Graphene

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Peroxynitrite and other reactive oxygen species (ROS) have shown contribution to oxidative stress-driven diseases including cardiovascular dysfunction. A precise detection of these species in biological systems is not only crucial for understanding the genesis and progression of diseases, but also for developing and evaluating effective therapies. In the past decade, selenium attracted the attention of many researchers for its antioxidative applications. Research studies have found that selenium plays a key role in redox regulation as a ROS modulator and as a catalytic cofactor of endogenous antioxidative systems.Our research study revealed the advantages of preparing electrochemical depositions of selenium as sensitive interfaces for peroxynitrite detection and quantification. In this regard, we fabricated highly sensitive and selective electrochemical sensors from a solution contains selenium dioxide in acidic medium. A series of glassy carbon electrodes (GCEs) have been modified with selenium nanoparticles, while another series of GCEs were modified with selenium-decorated graphene nanostructures for comparison purposes. The morphology and surface chemistry of the selenium and selenium-decorated graphene nanostructures were characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX). The electrochemical catalytic activities of these platforms were measured using cyclic voltammetry and chronoamperometry. The particle size of the prepared interfaces was determined by microscopic imaging particle analysis.It was shown that elemental selenium nanoparticles incorporated into graphene sheets enhanced the sensitivity toward peroxynitrite. Selenium tends to stimulate the current response to aliquots of peroxynitrite in solution. Additionally, it enabled the use of fewer positive potentials, resulting in better differentiation between peroxynitrite and other analytes that are sensitive to more positive potentials.