Microspheres with multilevel structure are widely used as removable catalysts, adsorbents, drug carriers and imaging contrast agents due to their hierarchical porosity. In this paper a facile wet chemical method for the synthesis of hierarchically nanostructured CuO chains assembled with small nanorods is reported. The as prepared nanomaterial is characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The autocatalytic response to nitrite ions is also carried out, which exhibits a wide linear range (0.004–3.7 mM), sound sensitivity (177.9 μA mg −1 dL −1 cm −2 ), highly reproducible response (R.S.D. of 2.0%), and an excellent long-term stability. The good analytical performance, low cost and straightforward preparation method make this novel electrode material promising for the development of effective nitrite sensors.