Time Resolved Electrochemical Quantification of Azanone (HNO) at Low Nanomolar Level

SUÁREZ, S. A.; BIKIEL, D. E.; WETZLER, D.; MARTÍ, M. A; DOCTOROVICH, F.

ANALYTICAL CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2013

0003-2700

Azanone (HNO, nitroxyl) is a highly reactiveand short-lived compound with intriguing and highly relevantproperties. It has been proposed to be a reaction intermediatein several chemical reactions and an in vivo, endogenouslyproduced key metabolite and/or signaling molecule. Inaddition, its donors have important pharmacological properties.Therefore, given its relevance and elusive nature (it reactswith itself very quickly), the development of reliable analyticalmethods for quantitative HNO detection is in high demand forthe advancement of future research in this area. During thepast few years, several methods were developed that rely onchemical reactions followed by mass spectrometry, high-performance liquid chromatography, UV−vis, or fluorescence-trappingbasedmethodologies. In this work, our recently developed HNO-sensing electrode, based on the covalent attachment ofcobalt(II) 5,10,15,20-tetrakis[3-(p-acetylthiopropoxy)phenyl] porphyrin [Co(P)] to a gold electrode, has been thoroughlycharacterized in terms of sensibility, accuracy, time-resolved detection, and compatibility with complex biologically compatiblemedia. Our results show that the Co(P) electrode: (i) allows time-resolved detection and kinetic analysis of the electroderesponse (the underlying HNO-producing reactions can be characterized) (ii) is able to selectively detect and reliably quantifyHNO in the 1−1000 nM range, and (iii) has good biological media compatibility (including cell culture), displaying a lack ofspurious signals due to the presence of O2, NO, and other reactive nitrogen and oxygen species. In summary, the Co(P)electrode is to our knowledge the best prospect for use in studies investigating HNO-related chemical and biological reactions.