Polyaniline Based Voltammetric and Potentiometric Sensors with Electrochemically-Influenced Ion-Discriminating Positions for Determination of Mercury(II)

An electroanalytical method for measuring mercury(II) has been proposed. A sulfosalicylate-doped-polyaniline (PA/SA) membrane, which was incorporated with mercury(II) ions, would be fine-tuned toward this ion's characters. Consecutive transfer of mercury(II) ions into/from the mass of PA/SA film correspondingly varies the characters of its ion-recognition sites, i.e., ion-discrimination positions in the membrane are matched with the complexing capability, size, and hard-soft nature of this ion. Really, the membrane is patterned with mercury(II) ion, and adequate analyte-receptor positions are created in the PA/SA membrane. This technique results in an exceedingly selective electrode for voltammetrically and potentiometrically measurements of mercury(II) ion. The best circumstances for sensor action were found out using a half fraction central composite design. The surface properties and composition of the as-prepared, patterned, and patterned-accumulated PA/SA membranes have been analyzed by SEM-EDS. The interference impression on the sensor signal by coexisted ions was investigated, and it was comprehended that only silver shows a significant interference. The sensor determines mercury(II) by accumulation/differential pulse anodic stripping voltammetry in the interval of 1.0 x 10(-9)-1.0 x 10(-4) M and potentiometrically in the molarities of 1.0 x 10(-8)-1.0 x 10(-3) with suitable selectivity.