Manganese Oxide/Hemin-Functionalized Graphene as a Platform for Peroxynitrite Sensing

Abstract

Peroxynitrite (ONOO−, PON) is a powerful oxidizing agent generated in vivo by the diffusion-limited reaction of nitric oxide (NO) and superoxide (O 2 ˙−) radicals. Under oxidative stress, cumulated peroxynitrite levels are associated with chronic inflammatory disorders and other pathophysiological conditions. The accurate detection of peroxynitrite in biological systems is important, not only to understand the genesis and development of diseases, but also to explore and design potential therapeutics. Herein, a manganese oxide/hemin-modified graphene interface is explored as a platform for peroxynitrite amperometric detection. Heminfunctionalized reduced graphene oxide was further modified with manganese oxide nanoparticles to provide a composite material with catalytic activity toward the electrochemical oxidation of peroxynitrite. The morphology of the composite material was characterized using scanning electron microscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, and UV-Vis absorption measurements. We investigated the electrocatalytic oxidation of peroxynitrite on graphite electrodes modified with the composite material using cyclic voltammetry and amperometry. The results showed that the incorporation of manganese oxide nanoparticles into graphene/hemin material enhances the catalytic detection of peroxynitrite compared to graphene/hemin alone.

Physicochemical properties and performance of graphene oxide/polyacrylonitrile composite fibers as supercapacitor electrode materials

“…This value did not differ significantly from the C/O ratios of pure GO. 40 The proportion of carbon increased as the rGOPKS was incorporated into CNFs, and the oxygen content decreased to 6.47%. This was because the high voltage applied during the electrospinning process caused the solvent and oxygen in the rGOPKS to evaporate.…”

Functional groups in graphene oxide

“…Typical EDX spectra OF GO shows carbon and oxygen atoms in the range of 0 to 1 keV and optimal C/O atomic ratio is between 2.1 and 2.9. 172,173 Fig. 10 Schematic illustration of grafting functional molecules on GO or rGO nanosheets, together with properties of resulting composite materials and their specific applications.…”

“…Typical EDX spectra OF GO shows carbon and oxygen atoms in the range of 0 to 1 keV and optimal C/O atomic ratio is between 2.1 and 2.9. 172,173…”

One-step simultaneous liquid phase exfoliation-induced chirality in graphene and their chirality-mediated microRNA delivery

“…2(B) and were consistent with an earlier report. 27 The energy-dispersive X-ray (EDX) spectra of l -graphene and d -graphene were recorded to analyze the elemental composition and their relative atomic weight ratios are listed in Table S1 (ESI†). For both l -graphene and d -graphene, nitrogen (N1s) and oxygen (O1s) were found to confirm the successful adsorption of tyrosine enantiomers.…”