Fabrication and characterization of highly-ordered Zinc Oxide nanorods on gold/glass electrode, and its application as a voltammetric sensor

Abstract

A novel voltammetric determination of amoxicillin (AMX) sensor has been fabricated, using zinc oxide nanorods (ZnO NRs) grown directly on gold/glass electrode. To prepare an electrode, ZnO NRs were directly grown on Au sputtered (thickness: 100nm) glass substrate (gold/glass electrode) with hydrothermal method. The directly synthesized ZnO NRs on the electrode expressively increases NRs attachment vertically, and increase its specific surface area. ZnO NRs/gold/glass electrode was characterized by field emission electron microscopy (FESEM), X-ray diffractometer (XRD) techniques, and this study has shown that the grown nanostructures are highly dense, uniform, and exhibited good crystal quality. The performance of the electrode was characterized with cyclic voltammetry (CV) and chronoamperometry (CA). The parameters of charge transfer coefficient (α), diffusion coefficient (D), electrode surface area (A), and catalytic rate constant (kh) were determined, and the results were studied. The electro catalytic current of AMX was found to have a linear relation to concentration over the range of 5×10−6 M–250×10−6 M (n=6). The good performance of the electrode is due to more immobilization on the well-aligned ZnO NRs arrays, and direct electron conduction between the ZnO NRs and the electrodes. Further, the sensor also showed a promising application for detecting AMX in capsule sample. The ease of fabrication, acceptable stability, and low cost of the modified electrode are the promising features of the proposed sensor.