Electrochemical Detection of Azanone

In this chapter, we describe the development and applications of an electrochemical azanone (HNO) sensor, based on the covalent attachment of a cobalt porphyrin (CoP) to a gold electrode. We begin by describing CoP reactivity and electrochemical properties and how they allow the design of an HNO-sensing scheme. The method is based on CoP reaction with azanone to form a Co III PNO − adduct, which upon oxidation results in a current intensity signal proportional to bulk HNO concentration, release of NO, and regeneration of the reactive state. The chapter then describes the analytical properties of the device, such as selectivity toward azanone and deficiency of interference with NO and other RNOS, linear response in the nM to µM range, compatibility with biological media, and the real-time response that allows to study the kinetics of reactions involving azanone. Finally, some applications in which the sensor has been used in chemical and biological studies are described.