Fabrication of an organic-inorganic hybrid composite bismuth film electrode for stripping analysis of trace Cd(Ⅱ) and Pb(Ⅱ)

A novel electrochemical sensor (organic-inorganic hybrid composite bismuth film electrode) was fabricated on a glassy carbon substrate electrode by an electrochemical co-deposition of polyaniline and bismuth followed by plating a thin layer of bismuth on the hybrid film. The hybrid composite bismuth film electrode was applied to detect trace Cd(Ⅱ) and Pb(Ⅱ) in 01 mol/L acetate buffer solution (pH 4.7) by square ware anodic stripping voltammetry. The influencing factors of stripping signals and the operational parameters were investigated in detail. The newly developed electrode revealed highly linear behavior in the examined concentration range from 1 to 90 μg·L-1 for both test metal ions, with the detection limits of 02 μg·L-1 and 05 μg·L-1 for Cd(Ⅱ) and Pb(Ⅱ) respectively, offering good coefficients of variation (CVs) of 43% and 61% for Cd(Ⅱ) and Pb(Ⅱ) (50 μg·L-1, n=50) respectively. After 30 d, the stripping peak currents for 50 μg·L-1 Pb(Ⅱ) and Cd(Ⅱ) on the composite film were detected decreasing 32% and 49%, respectively. The long term stability makes it possible to be applied in on-site monitoring of heavy metals in environmental water.