Network poly(bromophenol blue) (denoted as PBPB) films were electrochemically synthesized on the surface of glassy carbon electrode (GCE) by cyclic voltammetry and then the chemically modified electrode (denoted as PBPB-GCE) was fabricated. The characterization and growth mechanism of electrochemically synthesized PBPB films were firstly investigated by attenuated total reflection (ATR)-FTIR spectroscopy, in situ electron spin resonance (ESR) spectroelectrochemistry, qualitative analysis and electrochemical methods. This PBPB-GCE was successfully used to develop a novel and reliable electrochemical method for the determination of trace Cu (2+) by anodic stripping voltammetry. Based on the results from cyclic voltammograms or differential pulse voltammograms, the modified electrode showed excellent sensitivity toward the determination of Cu2+ in H2SO4 solution (pH 2.0). Under the optimized working conditions, there was a good linear relationship between anodic peak current and CU2+ concentration in the range of 1.0 x 10-81.0 x 10(-5) M with the detection limit of 3.5 x 10(-9) M (S/N = 3) in H2SO4 solution (pH 2.0). The current responses of successive measurements at the identical surface (n = 30) and at the renewed ones (n = 10) of PBPB-GCE were examined with relative standard deviation of 2.8% and 4.1%, respectively. It indicated that the chemically modified electrode showed good stability and reproducibility. The interference studies showed that the modified electrode exhibited excellent selectivity in the presence of other metal ions with a Cu2+ centration much higher than that of Cu. In the end, this proposed method was successfully applied to determine the concentration of Cu2+ in water samples. (C) 2007 Elsevier B.V. All rights reserved.