O-phenylenediamine-modified fiber electrodes for the detection of nitric oxide

Marilyn N. Friedemann, Scott W. Robinson, Greg A. Gerhardt

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251 Scopus citations

Abstract

Nitric oxide (NO.) sensors were prepared using o-phenylenediamine (o-PD) and Nafion to modify the surface of 30 μm diameter carbon fiber electrodes. These electrodes were compared with nickel porphyrin-type NO. sensors that have already been described. High-speed chronoamperometry, amperometry, and differential pulse voltammetty were used to compare the performance of sensors modified with various combinations of Nafion, o-PD, or nickel(II) meso-tetrakis(3-methoxy-4-hydroxyphenyl)porphyrin (Ni-TMPP), in order to determine which electrodes had the most sensitivity and selectivity for NO.. Our findings showed that electrodes treated with Nafion first, followed by o-PD, were very sensitive to NO., with a detection limit of 35 ± 7 nM. In addition, o-PD electrodes were also very selective against ascorbate (>600:1), dopamine (>300:1), and nitrite (>900:1). Moreover, in the range of 0-6 μM NO., o-PD electrodes displayed excellent linearity (R2 ≥ 0.997). In contrast, Ni-TMPP electrodes (with Nafion) had significantly poorer detection limits (76 ± 12 nM) and were less selective against dopamine (<5:1) and nitrite (<200:1). Ni-TMPP electrodes were also less linear than o-PD electrodes (R2 ≥ 0.911). Finally, we tested the in vitro and in vivo performance of the o-PD electrode in terms of its ability to detect NO. release from isolated rat renal arterioles and to measure NO. diffusion in the extracellular space of the rat brain.

Original languageEnglish
Pages (from-to)2621-2628
Number of pages8
JournalAnalytical Chemistry
Volume68
Issue number15
DOIs
StatePublished - Aug 1 1996

ASJC Scopus subject areas

  • Analytical Chemistry

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