Iridium oxide and palladium modified nitric oxide microsensor

An electrochemical microsensor, constructed by chemical modification of Nafion, poly(vinyl pyridine) (PVP), palladium and iridium oxide onto a platinum microelectrode, has been developed for the determination of nitric oxide (NO). This microsensor exhibits excellent catalytic activity toward NO oxidation, which is confirmed by differential pulse voltammetry. Cyclic voltammetry and differential pulse amperometry are also performed to measure NO. The catalytic peak current is found to be linear with the NO concentration in the range 5.8 x 10^-8 - 6.4 x 10^-6 mol/l, with a correlation coefficient of 0.9985. The detection limit of the microsensor is 1.5 x 10^-8 mol/l. In addition, the microsensor is also very selective with respect to interferents such as ascorbic acid, dopamine, and nitrite.