Entrapment of Metalloporphyrins Within an Electrodeposition Paint Layer as a Basis for Developing a Nitric Oxide Sensor

Ni tetra(4-N-methyl pyridyl)porphyrin was electrochemically entrapped within a polymer matrix formed by an anodic electrodeposition paint on the surface of Pt electrodes. Due to positive charges from the quaternised pyridinium side chains, the metalloporphyrin is soluble in water. By means of charge interactions between the positively charged metalloporphyrin and the negatively charged polymer backbone of the applied anodic electrodeposition paint, the entrapment of the metalloporphyrin in an insoluble polymer capsule prevents it from rapidly leaking off the electrode surface. The chemically modified electrodes obtained could be successfully applied to the sensitive determination of nitric oxide, and they displayed satisfactory stability for multiple nitric oxide measurements. The modified electrodes were employed for monitoring the decomposition of methylamine hexamethylene methylamine NONOate by continuous detection of the liberated nitric oxide.