关键词: 双向溶出伏安法, 修饰电极, 碳糊电极

Abstract: A novel Two_way Stripping Voltammetry method for simultaneous determination of Au 3+ and Cu 2+ was reported in this paper. Because of the strongly electrostatic attraction of carbon paste electrode towards Au(Ⅲ) ion at positive potential and the biochemical contribution of Gram_positive bacteria strain DO1, the ion can be determined by cathodic stripping voltammetry. At the same time, Cu(Ⅱ) is reduced readily under the catalysis of ultra_fine gold particles, thereafter it can be determined by anode stripping voltammetry. There is no interference between the determination of Au 3+ and Cu 2+ . A perfect liner relationship between the concentrations of cations and peak heights in the range of 0.2～1.0 μg/mL(Au 3+ ) and 2～10 ng/mL(Cu 2+ ) respectively were observed. The detection limit is 20 ng/mL for Au(Ⅲ), and 0.5 ng/mL for Cu(Ⅱ). The relative standard deviation of the response to 5 μg/mL Au 3+ and 60 ng/mL Cu 2+ are less than 3%.

Key words: Two_way stripping voltammetry, Bacteria modified electrode