Toxicity assessment of cyanide and tetramethylene disulfotetramine (Tetramine) using luminescent bacteria Vibrio-qinghaiensis and PbO2 electrochemical sensor

The toxicities of cyanide and tetramethylene disulfotetrarnine (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 mu g/mL for cyanide, 0.24 and 0.02 mu g/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 mu g/mL for cyanide, 0.21 and 0.01 mu g/mL for tetramine) and fast response time.