Wire-like nano-polyaniline deposited electrochemically in a reverse micelle electrolyte as a pH sensor

Wire-like polyaniline (PANI) films were successfully electrodeposited onto an indium tin oxide (ITO) substrate using a pulse galvanostatic method (PGM) in a reverse micelle electrolyte. The as-prepared PANI films were electrochemically analyzed by cyclic voltammetry and electrochemical impedance spectroscopy in 1 mol·L⁻¹ HClO₄ solution. It is found that the as-prepared PANI films are highly porous, exhibit the diameters of approximately 100 nm and the lengths exceeding 3 μm, and have favorable electrochemical activities. Furthermore, the as-prepared wire-like PANI films show a good linear relationship of the potentiometric response curve over the pH value range of 3–10 with a slope of 74.13 mV·pH⁻¹ in 0.5 mol·L⁻¹ K₂HPO₄ basal solutions. The results demonstrate that the prepared wire-like PANI films are promising pH sensors.