Highly efficient nonenzymatic glucose sensors based on CuO nanoparticles

In this work, copper nanoparticles using three different modes are synthesized and evaluated for electrochemical properties towards non-enzymatic glucose biosensors. Copper oxide nanoparticles thus obtained are characterized using X-ray diffractometer (XRD), Scanning Electron Microscope (SEM), transmission electron microscopy (TEM) and UV–Vis for their crystallinity, morphology and optical properties. The nanoparticles obtained using colloidal method (Cu-Colloid) give uniform phase of CuO and flower shaped morphology. The nanoparticles synthesized using solution combustion method with glycine (Cu-Gly) and hydrazine (Cu-Hyd) as fuel provide particles of irregular round shape and small flake-like structures respectively. The glucose electro oxidative current is highest for Cu-Colloid catalysts and could be due to the higher area of contact of the catalyst surface with the glucose. Cu-colloid particles with flower shaped morphology give wide linear response in the range of 1 μM to 850 μM along with the lowest limit of detection of 0.25 μM and highest sensitivity of 2062 μA mM⁻¹ cm⁻². Cu-Colloid catalyst show poor response on the presence of co-existing species on the blood sample when compared to its sensitivity towards glucose. The time response of Cu-Colloid particles for glucose detection is the least when compared to other two nanoparticles. Also, the Cu-Colloid particles show excellent reproducibility and stability that makes it a promising electrode for the non-enzymatic glucose bio-sensors.