Nanolayers of carbon protected copper oxide nanocomposite for high performance energy storage and non-enzymatic glucose sensor

Nanolayers of carbon shell protected nanorods-like copper oxide (CuO-NC) material were prepared via a simple chemical synthesis method. A small molecule compound such as dopamine (DA) was used as carbon precursors. The prepared nanostructured materials were characterized by various techniques and used as bifunctional electrode materials for supercapacitor and non-enzymatic glucose bio-sensing. The electrochemical performance suggested that bifunctional CuO-NC materials provided a high specific capacitance of 247 F g⁻¹ at a current density of 2.5 A g⁻¹. Remarkably, the specific capacitance increased as a function of cycle numbers, and a maximum capacitance of 364 F g⁻¹ was reached and sustained. Furthermore, the glucose-sensing performance was investigated and an excellent sensitivity value of 272.6 µA mM⁻¹ cm⁻² was achieved with a low limit of detection (0.14 µM). These excellent activities are mainly attributed to the presence of carbon shell, which acted as high active sites and enhanced electronic conductive paths for CuO-NC. The carbon shell also provided fast electron-transportation and effective protection of the nanorod structures under harsh redox condition, leading to excellent electrochemical activity.