Abstract: A sensor for detecting nitric oxide includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode, a polyelectrolyte film covering the exposed other portions working electrode and counter electrode, the polyelectrolyte film including at least one metalloporphyrins compound or metallophthalocyanine compound capable of increasing the rate of electrochemical oxidation-reduction reaction with nitric oxide and providing the detection of nitric oxide at a lower oxidation potential.