Low-temperature fabrication of ZnO nanorods/ferrocenyl-alkanethiol bilayer electrode and its application for enzymatic glucose detection

Abstract

A novel ZnO nanorods/ferrocenyl-alkanethiol (FcC11SH) bilayer structure was prepared and applied for the fabrication of glucose enzymatic biosensor. ZnO nanorod matrix was synthesized by low temperature aqueous method and provided a favorable environment for the immobilization of glucose oxidase (GOx). A monolayer of FcC11SH molecular was self-assembled on the surface of gold electrode and introduced a shuttling way for electronic communication between GOx and electrode. The morphology and structure of prepared ZnO nanorods were characterized by employing scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). Electrochemcial measurements of the sensor revealed a high and reproducible sensitivity of 27.8 μA cm(-2) mM(-1), and a linear range from 0.05 to 1.0mM with a detection limit of 20 μM. A relatively low value of Michaelis-Menten constant about 2.95 mM indicates the enhanced affinity of GOx to glucose. To the best of our knowledge, this is the first time to fabricate the glucose biosensor by using ZnO and FcC11SH bilayer structure.

Keywords: Enzymatic glucose sensor; Ferrocenyl–alkanethiol; Nanorods; Zinc oxide.