Toxicity Assessment of Cyanide and Tetramethylene Disulfotetramine （Tetramine） Using Luminescent Bacteria Vibrio-qinghaiensis and PbO= Electrochemical Sensor

The toxicities of cyanide and tetramethylene disulfotetramine （tetramine） were evaluated by two methods of luminescent bacteria and PbO2 electrochemical sensor. Vibrio-qinghaiensis, a kind of luminescent bacteria, can produce bioluminescence and the bioluminescence was decreased with the addition of toxicants. The toxicities of cyanide and tetrarnine were expressed as 10 min-EC50 value, which was the concentration of chemical that reduces the light output by 50% after contact for 10 min. Nano PbO2 modified electrode, a rapid toxicity determination method was also described in this work. By the PbO2 modified electrode, the current responses of Escherichia coli （E. coli） were changed with the addition of toxicants. The value of 10 min-EC50 was also provided with the PbO2 electrochemical sensor. Compared with the 10 min-EC50 and detection limits （38.38 and 0.60 μg/mL for cyanide, 0.24 and 0.02 μg/mL for tetramine） with luminescent bacteria, the PbO2 sensor provided a simple and convenient method with lower 10 min-EC50 and detection limits （26.37 and 0.52 μg/mL for cyanide, 0.21 and 0.01 μg/mL for tetramine） and fast response time.     

Nafion/Au溶胶自组装微铂传感器的研究及其在心肌细胞中NO水平测定中的应用

制备了一种新型的Nafion/Au溶胶修饰微铂传感器(Au溶胶颗粒的直径为7～14nm),并将该传感器应用于心肌细胞中NO水平的研究.实验结果表明,自组装制备的Nafion/Au溶胶修饰微传感器对NO有较高的灵敏度和良好的选择性,在1.0×10^-7～4.0×10^-5mol/L浓度范围内,NO的催化氧化电流与其浓度呈良好线性关系,检测限为5.0×10^-8mol/L.探讨了该修饰微传感器对NO的催化机理,研究了在L-精氨酸和乙酰胆碱刺激下心肌细胞内的NO释放.