Kong Bo, Tang Biyu, Liu Xiaoying, Zeng Xiandong, Duan Haiyan, Luo Shenglian, Wei Wanzhi
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Hunan, Changsha, PR China.
J Hazard Mater. 2009 Aug 15;167(1-3):455-60. doi: 10.1016/j.jhazmat.2009.01.010. Epub 2009 Jan 15.
A novel method for the simultaneous determination of cadmium(II) and copper(II) during the adsorption process onto Pseudomonas aeruginosa was developed. The concentration of the free metal ions was successfully detected by square wave anodic stripping voltammetry (SWASV) on the mercaptoethane sulfonate (MES) modified gold electrode, while the P. aeruginosa was efficiently avoided approaching to the electrode surface by the MES monolayer. And the anodic stripping peaks of Cd(2+) and Cu(2+) appear at -0.13 and 0.34V respectively, at the concentration range of 5-50 microM, the peak currents of SWASV present linear relationships with the concentrations of cadmium and copper respectively. As the determination of Cd(2+) and Cu(2+) was in real time and without pretreatment, the kinetic characteristics of the adsorption process were studied and all the corresponding regression parameters were obtained by fitting the electrochemical experimental data to the pseudo-second-order kinetic model. Moreover, Langmuir and Freundlich models well described the biosorption isotherms. And there were some differences in the amount of metal ion adsorbed at equilibrium (q(e)) and other kinetics parameters when the two ions coexisted were compared with the unaccompanied condition, which were also discussed in this paper. The proposed electrode system provides excellent platform for the simultaneous determination of trace metals in complex biosorption process.
开发了一种在铜绿假单胞菌吸附过程中同时测定镉（II）和铜（II）的新方法。通过巯基乙烷磺酸盐（MES）修饰的金电极上的方波阳极溶出伏安法（SWASV）成功检测了游离金属离子的浓度，而MES单分子层有效地避免了铜绿假单胞菌靠近电极表面。在5-50 microM的浓度范围内，Cd(2+)和Cu(2+)的阳极溶出峰分别出现在-0.13和0.34V，SWASV的峰电流分别与镉和铜的浓度呈线性关系。由于Cd(2+)和Cu(2+)的测定是实时的且无需预处理，因此研究了吸附过程的动力学特征，并通过将电化学实验数据拟合到伪二级动力学模型获得了所有相应的回归参数。此外，Langmuir和Freundlich模型很好地描述了生物吸附等温线。本文还讨论了两种离子共存时与单独存在条件相比平衡吸附的金属离子量（q(e)）和其他动力学参数的一些差异。所提出的电极系统为复杂生物吸附过程中痕量金属的同时测定提供了出色的平台。
