Electrospun CuO/NiO composite nanofibers for sensitive and selective non-enzymatic nitrite sensors

Abstract

A non-enzymatic electrochemical sensor based on the use of nanofibrous CuO/NiO as a catalytic probe was developed for the effective sensing of nitrite. One dimensional and strongly interconnected nanofibers with uniformly developed ultrafine nanograins were observed for the CuO/NiO composite nanofibers. The monoclinic crystalline structure of the CuO nanofibers was preserved even after composite formation with NiO. The electrocatalytic activity of the prepared CuO/NiO nanofibers toward nitrite oxidation was investigated under neutral conditions. When utilized as a potent non-enzymatic sensor, the CuO/NiO nanofibers showed excellent amperometric performance, including a lower sensing limit, soaring sensitivity, and a broad linear array, respectively, of 0.5 μM, 282.72 μA mM⁻¹ cm⁻², and 0.001–5 mM. Furthermore, the remarkable selectivity and stability achieved for the as-fabricated sensors endorse its real sample analysis with human serum. Thus, these findings overcome the hurdles of existing non-enzymatic nitrite sensor probes and open up new possibilities in exploring an efficient and economical approach toward the development of electrochemical probes for nitrite detection.