Therapeutic carbon nanomaterial H2S oxidants for biological polysulfide synthesis

Oxidized-carbon nanoparticles prepared by a process that comprises contacting one or more carbon nanoparticulate materials with concentrated nitric acid or fuming nitric acid, optionally dissolved in concentrated sulfuric acid or fuming sulfuric acid, to form a population of oxidized-carbon nanoparticles;

• wherein the one or more carbon nanoparticulate materials are selected from the group consisting of graphene, graphene nanoribbons, graphene oxide, graphite, graphite oxide nanoribbons, carbon black, hydrophilic carbon clusters, coal, activated coal and activated charcoal;
• wherein the oxidized-carbon nanoparticles form a dispersion in water in the absence of an exogenously-supplied functionalized solubilizing agent and form a non-settling dispersion in water at a concentration of about 1 to about 5 mg/mL,
• said dispersion being stable to settling at ambient room temperature for at least seven days and exhibiting an absorbance maximum at about 220 nm,
• said oxidized-carbon nanoparticles being generally discoid particles and wherein said particles have diameters of about 5 to about 30 nm and thicknesses of about 0.3 to about 2 nm, containing about 9 to about 15 percent carbonyl groups by X-ray photoelectron spectroscopy (XPS), and passing through a 0.22 μm pore size polyethersulfone (PES) filter membrane.