Oxidation of Nitric Oxide at a Porphyrinic-Based SensorNew Results from Rotating Disk Experiments

Abstract

An amperometric sensor for the determination of nitric oxide based on its oxidation on a glassy carbon electrode modified with electropolymerized vanillin porphyrin [tetrakis(3-methoxy-4-hydroxyphenyl)porphyrin] film and Nafion is described. Our results show that the anodic oxidation of NO at the modified electrode is the result of a catalytic effect induced by the porphyrinic modifier, that acts as a 3D system. The effect of film thickness of both porphyrinic modifier and Nafion on the NO response is tested. The results of rotating disk electrode experiments are presented and a general mathematical model of the working sensor is also given.

Nanostructured Electrochemical Sensor Based on Dense Gold Nanoparticle Films

“…The suggested electrocatalytic oxidation mechanism is that NO in solution first loses an electron to form NO + with the help of Au nanoparticles at the electrode surface. The formed NO + can then be further oxidized to form other more stable nitrogen products 6 (A) Cyclic voltammograms of a bare ITO electrode in (a) pH 2.0 PBS containing 0.5 mM NaNO 2 , and a PEI/[(PSS/PAH) 2 /PSS/Au NP ] 3 -modified electrode in pH 2.0 PBS containing (b) 0, (c) 0.05, (d) 0.15, (e) 0.25, (f) 0.35, (g) 0.45, and (h) 0.55 mM NaNO 2.…”

Electrochemical Sensor for Oxidation of NO Based on Au‐Pt Nanoparticles Self‐assembly Film

“…The formed NO ＋ can then be further oxidized to form other more stable nitrogen products. 17 Figure 5b was the calibration curve corresponding to the amperometric responses of Au-Pt bimetallic nanoparticles film/GC electrode at 0.76 V. The Au-Pt bimetallic nanoparticles film/GC electrode has a high current response, which suggests that the Au-Pt nanoparticles self-assembly film/GC electrode has a high sensitivity to NO. Furthermore, for the Au-Pt bimetallic nanoparticles film/GC electrode, a linear dependence of the peak current on the NaNO 2 concentration in the range from 0 to 0.65 mmol•L -1 is obtained, with the detection limit being about 0.04 mmol•L -1…”

Studies on CuTAPc-nanotube-modified electrodes as chemical sensors for NO

“…Although this range does not overlap or conflict with the expected range (of 1.0 nm-10 μM) that we expect for the sensor measurement of NO, it would be more accurate to eliminate any possible contributions from nitrite oxidation in voltammetric analysis. Meanwhile, a less-defined peak was also observed at an oxidation potential around 0.6-0.64 V which could be attributed to the presence of a small amount of NO [34][35][36]. This can be seen in figure 2 at a nitrite concentration of 150 μM.…”