Zlatev Roumen, Magnin Jean-Pierre, Ozil Patrick, Stoytcheva Margarita
Autonomous University of Baja California, Institute of Engineering, Blvd. Benito Juares S/N 21280, Mexicali, Baja California, Mexico.
Biosens Bioelectron. 2006 Mar 15;21(9):1753-9. doi: 10.1016/j.bios.2005.09.001. Epub 2005 Oct 11.
The adsorption (fixation) of bacteria Acidithiobacillus ferrooxidans on Hg and Cu metallic surfaces was qualitatively studied owing to two independent methods: frequency measurement using a quartz crystal microbalance and light absorption measuring at the Hg/bacterial culture interface. A method using a dropping mercury electrode (DME) allowed quantifying this bacterial fixation. Determining the superficial tension at Hg/bacterial culture interface led to determine bacteria adsorption on Hg through the Gibbs isotherm. A modified stripping voltammetry was proposed taking benefit of both bacterial adsorption on Hg surface and metal fixation capacity on biomass. Metal preconcentration on the biologically modified Hg electrode appeared to improve the measurement sensitivity of differential pulse anodic stripping voltammetry (DPASV). The height of the detected peaks was thus increased of 17.6% for copper, 48.4% for lead, and 132% for cadmium determinations compared to those obtained with an unmodified mercury electrode. Such augmentation depended on bulk bacteria concentration and bacteria preconcentration.
利用两种独立的方法对氧化亚铁硫杆菌在汞和铜金属表面的吸附（固定）进行了定性研究：使用石英晶体微天平进行频率测量以及在汞/细菌培养物界面处测量光吸收。一种使用滴汞电极（DME）的方法能够对这种细菌固定进行定量。通过吉布斯等温线，测定汞/细菌培养物界面处的表面张力可确定细菌在汞上的吸附情况。利用细菌在汞表面的吸附以及金属在生物质上的固定能力，提出了一种改进的溶出伏安法。在生物修饰的汞电极上进行金属预富集似乎提高了差分脉冲阳极溶出伏安法（DPASV）的测量灵敏度。因此，与未修饰的汞电极相比，铜测定的检测峰高增加了17.6%，铅测定增加了48.4%，镉测定增加了132%。这种增加取决于本体细菌浓度和细菌预富集情况。
