Determination of nitric oxide with ultramicrosensors based on electropolymerized films of metal tetraaminophthalocyanines

Preparation and electrochemical responses to nitric oxide (NO) of the electropolymerized films of metal tetraaminophthalocyanines (MTAPc, M=Co, Ni, Cu) are studied to test them as molecular devices for design and construction of amperometric ultramicrosensors for selective and sensitive determination of NO. The ultramicrosensors based on electropolymerized films of MTAPc and Nafion, are found to show a low detection limit, high selectivity and sensitivity to NO determination. The potential interference from some endogenous electroactive substances in biological tissues, such as catecholamines and their metabolites, ascorbic acid (AA), uric acid (UA), and nitrite (NO₂⁻), the metabolite of NO at the concentrations higher than those in biological systems could be eliminated by using a technique of DPV or DPA and further coating the modified ultramicrosensors with a layer of Nafion.