Nano-composite of Co3O4 and Cu with enhanced stability and catalytic performance for non-enzymatic electrochemical glucose sensors

Nanostructured Co3O4 with near-cubic morphology was synthesised using the solvothermal method, and a non-enzymatic electrochemical glucose sensor (Co3O4-CuNPs/Pt) was successfully constructed by dropping and potentiostatic depositing technologies. The obtained Co3O4 and Co3O4-CuNPs were characterised and investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Quantitative analysis of glucose was performed using the amperometric (i-t) method, and a plot of current difference versus concentration of glucose was linear in the range 0.5-336 mu M, with a linear correlation coefficient (R-2) of 0.9989 and limit of detection (LOD) of 0.43 mu M. When the linear range was reduced to 0.5-76.5 mu M, R-2 and LOD were 0.9997 and 0.17 mu M, respectively. The sensitivity of the sensor was evaluated as 3.58 x 10(4) and 4.03 x 10(4) mu A mu M-1 cm(-2) for the above two linear ranges, respectively. This novel sensor produced satisfactory reproducibility and stability and was applied to monitor trace amounts of glucose in human serum samples.