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 1 H -pyrrole-1-hexanoic acid (monomer L ) on glassy carbon disks with very good reproducibility in the elaboration process. Poly L 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 poly L 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. Poly L 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.