A novel electrochemical sensor was fabricated by co-deposition of Pt nanoparticles and Fe(III) on glassy carbon electrode (GCE). XPS, XRD and FE-SEM techniques were used for characterization of the surface structure. It was found that the co-deposited nanoparticles with average size of about 60 nm uniformly distributed on the electrode surface, with the iron element in Fe(III) state and the platinum nanoparticles of a size of about 6 nm in Pt(0) state of face-centered cubic structures. This sensor showed substantial catalytic ability toward the oxidation of nitrite anions. About 240 mV decreased overpotential and 2.6 fold enhanced voltammetric current were achieved at the optimized condition. A linear response in the range of 1.1×10 −2–1.1×10 −6 M nitrite and a detection limit of 4.7×10 −7 M ( s/ n=3) were obtained. The nitrite sensor had also good stability and anti-interference ability.