Toxicity assessment of water is of great important to the safety of human health and to social security because of more and more toxic compounds that are spilled into the aquatic environment. Therefore, the development of fast and reliable toxicity assessment methods is of great interest and attracts much attention. In this study, by using the electrochemical activity of Shewanella oneidensis MR-1 cells as the toxicity indicator, 3,5-dichlorophenol (DCP) as the model toxic compound, a new biosensor for water toxicity assessment was developed. Strikingly, the presence of DCP in the water significantly inhibited the maximum current output of the S. oneidensis MR-1 in a three-electrode system and also retarded the current evolution by the cells. Under the optimized conditions, the maximum current output of the biosensor was proportional to the concentration of DCP up to 30 mg/L. The half maximal inhibitory concentration of DCP determined by this biosensor is about 14.5 mg/L. Furthermore, simultaneous monitoring of the retarded time (Δt) for current generation allowed the identification of another biosensor signal in response to DCP which could be employed to verify the electrochemical result by dual confirmation. Thus, the present study has provided a reliable and promising approach for water quality assessment and risk warning of water toxicity.

水的毒性评估对于人类健康的安全和社会保障至关重要，因为越来越多的有毒化合物泄漏到水生环境中。因此，快速，可靠的毒性评估方法的发展引起了广泛的关注，并引起了广泛的关注。本研究以Shewanella oneidensis MR-1细胞的电化学活性为毒性指标，以3,5-二氯苯酚（DCP）为模型毒性化合物，开发了一种新型的水毒性评估生物传感器。令人惊讶的是，水中的DCP明显抑制了沙门氏菌的最大电流输出。三电极系统中的MR-1还可延缓细胞产生的电流。在最佳条件下，生物传感器的最大电流输出与DCP的浓度成正比，最高可达30 mg / L。通过该生物传感器测定的DCP的半数最大抑制浓度为约14.5mg / L。此外，对电流的延迟时间（Δt）的同时监控允许响应DCP识别另一个生物传感器信号，该信号可用于通过双重确认来验证电化学结果。因此，本研究为水质评估和水毒性风险预警提供了可靠且有前途的方法。