Electrochemical Signature of Peroxynitrite on Modified Boron-Doped Diamond Electrodes

Abstract

Endogenous and exogenous reactive oxygen and nitrogen species such as peroxynitrite have serious damaging effects on cell components and cell function. Peroxynitrite has emerged as a reactive species that is linked with oxidation and/or nitration of biomolecules. In biological context, peroxynitrite is the product of the combination between superoxide and nitric oxide radicals through a diffusion-limited reaction. The short lifespan and fast reactivity of peroxynitrite are adding more challenges to measure its concentration under physiologic conditions. Although several methods have been established for peroxynitrite detection in aqueous solutions, they are still facing the problem of real-time quantification. In this paper, the electrochemical behavior of peroxynitrite has been studied boron-doped diamond electrodes (BDD). Recently, BDD have been successfully worked as platforms for electrochemical detection of various analytes in biological and environmental systems. BDD electrodes provide a wide potential window and a low background current that creates an excellent platform to fine-tune the surface for optimized detection of peroxynitrite. In this research study, the direct electrochemical oxidation of peroxynitrite on modified BDD electrodes was recorded and investigated. A wide range of physicochemical characterizations were conducted to study the catalytic oxidation of peroxynitrite on modified BDD electrodes. The same modified BBD platform is used to develop a selective peroxynitrite sensor that can further be developed into a tool that can be used for both electrical stimulation and monitoring of peroxynitrite levels under physiologic conditions.