Ultrasensitive modified electrode based on poly(1H-pyrrole-1-hexanoic acid) for Pb(II) detection

Metal ion complexing modified electrodes were obtained by oxidative electropolymerization of 1H-pyrrole-1-hexanoic acid (monomer L) on glassy carbon disks with very good reproducibility in the elaboration process. PolyL films were characterized by scanning electron microscopy, atomic force microscopy, electrochemical techniques, and their hydrophilic character was evaluated by contact angle measurements. Using chemical preconcentration-anodic stripping technique at optimized parameters (pH, open circuit preconcentration time, reduction potential and time) linear calibration curves with ranges from 3 × 10−11 M to 8 × 10−8 M, and from 5 × 10−11 M to 7 × 10−8 M were obtained for Pb(II) ions using two thickness of polyL films. Their corresponding detection limits (S/N = 3) were 20pM and 30pM, respectively. These limits are favorable in comparison with other modified electrodes developed for Pb(II) detection. PolyL modified electrodes were used for electroanalysis of Pb(II) ion in tap waters, and the results were validated by GF-AAS method. Also, the modified electrodes presented very good stability over time.