Electrodes modified with poly-benzidine films are chemically stable in the pH range between 0 and 7, and can be cycled from -0.200 to 0.850 V with no evidence of decomposition. Consequently, in this potential range, they can be used as electrode material for oxidation or reduction of different species. One interesting property of this modified electrode is its capacity to capture and quantify Ag(I) ion present in solution. To obtain reproducible results, the accumulation step was carried out in a AgNO3 solution with acetate buffer at pH = 7. After reduction to Ag(0) in the same solution, the determination step was performed by cyclic voltammetry. The analytical response corresponds to silver oxidation to Ag(I), and the amount of silver incorporated into the film was determined from the charge of the anodic peak. The potential use of this method for analytical determination of silver is discussed.
modified electrodes; poly-benzidine; electroanalysis; silver(I)
