Characterization, growth mechanism and application of network poly(bromophenol blue)

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 Cu2+ 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 × 10−8–1.0 × 10−5 M with the detection limit of 3.5 × 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 concentration much higher than that of Cu2+. In the end, this proposed method was successfully applied to determine the concentration of Cu2+ in water samples.