The present work describes the design of a Co NPs-PEDOT-GE nanocomposite- modified GCE and its electrocatalytic properties toward the oxidation of nitrite. Compared with the Co NPs-GE/GCE (b) or PEDOT-GE/GCE (c), the as-prepared Co NPs-PEDOT-GE/GCE (d) exhibits remarkably enhanced electrocatalytic activity towards nitrite