Hybrid electrochemical/electrochromic Cu(II) ion sensor prototype based on PANI/ITO-electrode

[Display omitted] •Polyaniline (PANI) electrochromic films were deposited on Indium tin oxide (ITO).•Electrochromic performance of PANI/ITO-modified electrodes were investigated.•Sensitivity of PANI/ITO-modified electrode toward Cu(II) ions was evaluated.•Chemical structure of synthesized PANI layer was evaluated by FTIR. Conducting polymer polyaniline (PANI) based electrochromic films were electrochemically synthesized on indium tin oxide (ITO) covered glass electrodes and their electrochromic performances were investigated by spectroscopic methods before and after the incubation in Cu(II) ion containing aqueous solution. Chemical structure of synthesized PANI layer was evaluated by FTIR. The electrochromic performance of PANI film was determined by measuring of spectroscopic signals before and after the incubation of PANI film coated electrode in Cu(II) ion containing solution. During the change of potential, which was applied to PANI-modified electrode, the colour of PANI thin film turned from green to blue, dark blue, colorless and yellow dependently on the applied potential. Significant alteration of electrochromic effect was observed after the incubation of PANI/ITO-modified electrode in Cu(II) ion containing solution. It was also found that the PANI films exhibited highest optical contrast if potential profile of 0.200mV vs Ag/AgCl(3MKCl) was applied. Applicability of PANI/ITO-electrode for electrochromic effect based determination of Cu(II) ions was also evaluated. Investigated PANI/ITO-electrode response to Cu(II) ions indicates that PANI/ITO-electrodes can be used for both chronoamperometric and electrochromic detection of Cu(II) ions.