Electrochemical and spectrophotometric study of the behavior of electropolymerized nickel porphyrin films in the determination of nitric oxide in solution

We describe in this paper an electrochemical and spectrophotometric study of the behavior of an electropolymerized nickel porphyrin film as a sensor for the determination of nitric oxide (NO) in aqueous solution. Our results show that the anodic oxidation of NO at the modified electrode may not be the result of a catalytic effect induced by the porphyrinic complex. However, the current (measured by differential pulse amperometry) and calculated NO concentration showed a linear relationship in the range 15 nM-6 mu M in aerobic phosphate buffer solution (pH 7.4). These results provide a fruitful example of calibration of such electrochemical sensors for the selective detection of NO with a calculated detection limit, at a signal-to-noise ratio of three, equal to 1.5 nM.