Electrochemical synthesis of Alizarin Red S doped polypyrrole and its applications in designing a novel silver (I) potentiometric and voltammetric sensor

- The PPy/ARS modified electrode was fabricated and used for quantitative and selective enrichment of silver ions.
- The electrode was useful for potentiometric and voltammetric determination of silver (I) ion.
- The sensor was used for analysis of silver in real samples with a detection limit of 4.6 × 10− 10 M.

Conducting polymer modified electrodes based on the incorporation of the Alizarin Red S (ARS) into polypyrrole (PPy) film during electropolymerization were used for potentiometric and voltammetric detection of silver (I) ion in solutions. In the potentiometric mode, the electrode showed a good Nernstian slope of 59.6 ± 0.4 mV decade− 1 with a wide linear activity range of 5.0 × 10− 8 to 6.3 × 10− 3 M for Ag+ cation and a detection limit of 2.5 × 10− 8 M. The PPy/ARS modified electrode was also used for preconcentration and differential pulse anodic stripping voltammetric measurements of silver (I) ion in solution. A linear relationship was observed between the voltammetric responses of the PPy/ARS modified electrode and the concentration of Ag+ ion ranging from 9.2 × 10− 10 to 2.8 × 10− 6 M with a detection limit of 4.6 × 10− 10 M. The effect of some transition metal ions on the response of the electrode was studied and the corresponding results showed that there is not any significant interference in potentiometric and voltammetric determination of silver (I) ion except for the mercury (II) ion. Finally, because of a lower detection limit of anodic stripping voltammetric measurement compared to the potentiometric method, the former technique was applied for determination of silver (I) ion in real samples.