Preparation of single-walled carbon nanotubes attached with NiO and CoO as a flexible non-enzymatic glucose sensor

A flexible buckypaper attached with NiO and CoO (NiO-CoO-BP) was fabricated for electrochemical detection of glucose, exhibiting the characteristics of high conductivity, selectivity, sensitivity and a wide detection range. NiO-CoO-BP comprises two arc discharge-synthesized single-walled carbon nanotube (SWCNT) types. The bottom is a supporting layer of high-crystallinity, high-conductivity purified SWCNT networks, and the upper is a catalytic active layer of SWCNTs loaded with NiO-CoO nanoparticles. The two SWCNT types were combined via vacuum filtration to form a membrane structure. A thermal field scanning electron microscope was used to characterize the morphology of NiO-CoO-BP, while an X-Ray diffractometer and Raman spectroscopy were employed to determine its structure. Under optimized conditions, the electrochemical test of the flexible glucose sensor constructed with NiO-CoO-BP exhibited a wide linear range of 2 to 20 mM, a sensitivity of up to 3789.17 μA·mM⁻¹·cm⁻², and a low detection limit of 37 μM. The test results of this work indicate that flexible NiO-CoO-BP composed of purified SWCNTs and NiO-CoO-SWCNTs has great application prospects in wearable biosensors.