A Sensitive Electrochemical Glucose Biosensor Based on Flower-Shaped Zinc Oxide Nanostructures

Abstract

In this work, flower-shaped zinc oxide nanostructures were used to develop sensitive electrochemical glucose biosensor. The flower-shaped zinc oxide nanostructures were prepared by solvothermal method, which was different from the previous method [1], and characterized by scanning electron microscope and X-ray diffraction spectroscopy. A novel glucose biosensor was fabricated based on the immobilization of glucose oxidase (GOx) on the flower-shaped zinc oxide nanostructure. Flower-shaped zinc oxide with large specific surface area can load large amounts of glucose GOx, and provide excellent microenvironment for the immobilized enzyme[2,3,4,5]. Fig. 1 shows the amperometric response of the GOx/Nafion/GCE and GOx/ZnO/Nafion/GCE in pH 7.0 air-saturated PBS containing different concentrations of glucose at –0.37 V applied potential. The proposed biosensor shows a wide linear range from 0.005–1.6 mM, high sensitivity of 15.6 mA M−1 cm−2, and low detection limit of 0.004 mM. The performance of the GOx/ZnO/Nafion/GCE is much better than that of GOx/Nafion/GCE. The resulting biosensor with excellent selectivity, stability and reproducibility can be successfully applied in the detection of glucose at –0.37 V in human serum samples.