In this article, TiO2-modified ZnO nanotube arrays (NTAs) are successfully synthesized and used to prepare a nonenzymatic biosensor for the detection of glucose and hydrazine hydrate. In brief, the ZnO@TiO2 NTAs are synthesized on zinc foil by two steps of simple hydrothermal method. Therefore, it can be directly used as a working electrode and is not needed to be modified to other electrode surface by any means to form a sensor. In the oxidation of glucose and reduction reaction of hydrazine hydrate, it exhibits excellent electrocatalytic performance. Moreover, it has high sensitivity, a fast response time (less than 3 s), and a detection limit as low as 0.5 mu M (S/N = 3) toward glucose and hydrazine hydrate respectively. In the selectivity of the target analyte, the Zn-ZnO@TiO2 nanocomposite electrode can effectively resist the influence of different interferent, including uric acid, dopamine, and l-cysteine.