A Highly Sensitive Amperometric Glucose Biosensor Based on a Nano-cube Cu2O Modified Glassy Carbon Electrode

A highly sensitive amperometric glucose biosensor was fabricated by the synthesized cuprous oxide (Cu2O) nanocube. The synthesized nano-Cu2O and modified electrode were characterized using X-ray diffraction and scanning electron microscopy. The results showed that the obtained samples were nanocube Cu2O. The electrochemical properties of the modified sensors were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). The CV behavior of nanocube Cu2O modified sensor was investigated in 0.1 M PBS (pH 7.4, containing 0.1 mM glucose). The prepared sensor presented remarkably enhanced electrocatalytic activity toward glucose detection. Linear responses of the sensor to glucose were observed in the concentration range from 5.0 x 10(-6) M to 4.0 x 10(-3) M (R-2 = 0.9983), with a detection limit of 6.8 x 10(-7) M (S/N = 3). CA results showed no interference from potential interfering species, such as uric acid, ascorbic acid, and D-fructose. The developed sensor also exhibited good repeatability and stability, and was successfully applied to detect glucose in real urea samples.