P142 – Graphene-Based Nanostructured Interfaces for Selective and Sensitive Peroxynitrite Detection

Peroxynitrite (PON, ONOO−) is a strong oxidizing and/or nitrating metabolite formed by the diffusion-controlled reaction of nitric oxide (•NO) and superoxide (O2•−). Elevated peroxynitrite levels are associated with chronic inflammatory disorders including neurological and vascular diseases, as well as a number of other pathophysiologic conditions. The accurate quantification of this analyte in biological systems is of paramount importance not only to understand the genesis and development of diseases at the tissue/cellular level, but also to assess potential therapies. Our lab has been exploring various designs of surfaces based on metalloporphyrins in polymeric matrices as well as metal-decorated carbon nanotubes and graphene-based nanostructures for electrochemical sensing of peroxynitrite. Recently, we have published some work describing sensors based on polymerized hemin both as a stand-alone component and in combination with sulfur-containing conductive polymers or on carbon-based nanostructures. In the current work we will present results on the performance of combinations of metal or metal oxides, carbon nanostructures, and polymeric matrices for selective and sensitive detection of peroxynitrite. We will present various physicochemical characterizations of these PON-sensitive surfaces, including scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet/visible (UV), and Raman spectroscopy. We will compare and contrast the performance of the various combinations in terms of PON sensitivity using cyclic voltammetry and dose–response chronoamperometry.