In this work, one dimensional self-ordered Nb2O5 nanotube arrays were grown from Nb substrate by anodization method and were modified with optimum amounts of chitosan (CS) and carboxyl-Fe3O4 nanoparticles. These nanocomposites were characterized by SEM, XRD, and XPS and used as electrode materials for the direct detection of atrazine traces in aqueous solution. The test signals were obtained from the interaction between anti-atrazine monoclonal antibody and atrazine and recorded using via differential pulse voltammetric (DPV) method in electrochemical system. These modified one-dimensional Nb2O5 nanotube arrays showed the linear detection ranges of 0.04 ng/mL-0.6 ng/mL and a detection limit of 0.018 ng/mL for atrazine under the optimized conditions. These above results indicate that these Nb2O5 nanotube arrays are promising candidates for electrochemical sensors. (C) 2017 Elsevier B.V. All rights reserved.