Electrochemically Generated Recognition Sites in Self‐doped Polyaniline Modified Electrodes for Voltammetric and Potentiometric Determination of Copper(II) Ion

Abstract

AbstractChemical recognition elements for copper(II) ion have been generated in electrodes modified with poly(aniline‐co‐metanilic acid), P(An‐co‐MA), membrane and the resulting electrodes were used as selective sensors for voltammetric and potentiometric determination of this ion in an extended pH range. The P(An‐co‐MA) membrane was electrodeposited from aqueous mixed monomer solutions of An and MA, without the presence of a supporting electrolyte. For generating the recognition elements, P(An‐co‐MA) modified electrodes were subjected to several consecutive reduction/oxidation potential steps in copper(II) ion solution. It seems that during these potential steps, the receptor sites of the membrane are adjusted to the size, complexing property and hard/soft nature of copper(II) ion. This electrochemically mediated templating process, provided a selective sensor for determination of copper(II) ion. The results of preconcentration/differential pulse anodic stripping voltammetry, indicated analytical relation between the peak current and concentration of copper(II) from 1.0×10−9 to 1.0×10−4 M. The interference effect of various metal ions was explored and it was found that only mercury and silver ions show a considerable interference. The sensor exhibited selective potentiometric response for copper(II) over a wide concentration range (1.0×10−8 to 1.0×10−3 M) with a Nernstian slope of 27.9±0.3 mV per decade of copper(II) ion activity.