Functionalised zinc oxide nanotube arrays as electrochemical sensors for the selective determination of glucose

In the present study, highly oriented single-crystal zinc oxide nanotube (ZnO-NT) arrays were prepared by a trimming of ZnO nanorods along the c-axis on the gold-coated glass substrate having a diameter of 100-200-nm and a length of ~1 μm using a low-temperature aqueous chemical growth process. The prepared (ZnO-NT) arrays were further used as electrochemical enzyme-based glucose sensors through immobilisation of glucose oxidase by the physical adsorption method in conjunction with a Nafion coating. The electrochemical response of the sensor was found to be linear over a relatively wide logarithmic concentration range from 0.5 × 10^-6 to 12 × 10^-3 M. The proposed sensor showed a high sensitivity of 69.12 mV/decade with R=0.9934 for sensing of glucose. A fast-response time less than 4 s with good selectivity, reproducibility and negligible response to common interferents such as ascorbic acid and uric acid prevailed.