Accurate and quantitative monitoring of nitrite concentration is quite important for food safety and environmental pollution. In the present work, platinum and tricobalt tetroxide nanocomposite (Pt@Co3O4) was firstly proposed for nitrite detection and prepared via a facile process. The transmission electron microscope images exhibit that the platinum and Cobalt oxide nanoparticles were intertwined and embedded, the special structure can improve the electrocatalytic performance during nitrite determination. A novel electrochemical sensor with low-cost and high sensitivity was built based on Pt@Co3O4. Amperometric measurements of the modified electrode revealed a wide linear range for nitrite determination from 3 mu M to 70 mM with a low detection limit and a sensitivity of 0.97 mu M and 40.29 mu A mM(-1) cm(-2), respectively. Chronoamperometry and cyclic voltammetry were used to calculate the kinetic parameters, which proved that the Pt@Co3O4 nanocomposite has a high catalytic efficiency in promoting the electron transfer kinetics of nitrite oxidation at the modified electrode. Besides, the selectivity, stability and repeatability of modified electrode were also investigated, and the results suggested that the built sensor has a possible application for effective detection of nitrite in practical samples. (C) 2019 The Electrochemical Society.