Electrochemical S-Nitrosothiol Detection (2011)

Undergraduates: Steven Nutz, Dan Riccio

Faculty Advisor: Mark Schoenfisch
Department: Chemistry

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Nitric Oxide (NO) is a highly reactive and crucial signaling molecule for numerous physiological systems. It will combine with a wide array of biological molecules and its reaction with endogenous thiols to form S-nitrosothiols (RSNOs) is considered an important mechanism in vasodilation, inhibition of platelet aggregation and neurotransmission. Thus, the levels of RSNOs are important indicators of various physiological functions and disease states. Previous studies indicate that the release of NO from RSNO’s can be catalyzed by heat, trace metals or by irradiation. Herein, we describe the detection of small molecule RSNOs (e.g., S-nitrosoglutathione (GSNO)), via a copper ion catalyzed release of NO and its subsequent electrochemical detection with a 20% 17FTMS/MTMOS xerogel-derived NO selective electrode. Multiple trace metal decomposition pathways of RSNOs using varied concentrations and sources of copper (e.g., copper (II) nitrate, copper (I) chloride) are evaluated. Additionally, reducing agents such as glutathione, cysteine, ascorbic acid, and dithiothreitol are examined to elucidate any effects on sensitivity, response time, or linear range of the sensor.