新型微流控微生物燃料电池传感器在生物毒性物质定量检测中的响应机制研究

.Due to the advantage of direct conversion of input signal to electric current for microbial fuel cell based biosensor, it is considered as a promising technology in environmental application and biological engineering. Here， a novel microfluidic microbial fuel cell based biosensor will be used for quantitative analysis of bacterial biotoxin and the mechanism of the bacteria activity responding to biotoxin will be studied. Firstly, to overcome the disadvantages of biosensor (e.g. slow response and instable signal output), a novel microfluidic microbial fuel cell based biosensor is developed by taking the advantage of microfluidic devices, which are small volume, fast response and well-defined controllable fluidic state. The anode and cathode in the micro-MFC are separated by inherent laminar flow and thus resulting in omitting membrane. The key design factors will be optimized based on computational fluid dynamics. Then, the improved biosensor will be employed for quantitative analysis of bacterial biotoxin. Furthermore, the response mechanism will be studied by examining the effect of biotoxin concentration and exposure time on bacterial activities, which is determined by electric current change. Finally, parameter optimizing experiments will be conducted to improve the biosensor sensitivity and output signal stability.

基于微生物燃料电池的传感器由于具有能将目标检测物质直接转化为电流信号的优点，在环境保护，生物化工等领域有着广阔的应用前景。本申请课题将微生物燃料电池传感器用于生物毒性物质的定量检测并揭示传感器电流信号对生物毒性物质的响应机制。首先，针对现有微生物燃料电池型传感器存在的响应速度慢，输出信号不稳定等缺点，通过将微流控芯片与微生物燃料电池传感器相整合，利用微流控芯片体积小，响应快，内部流态明确可控等优点来克服上述缺陷，并利用微流控芯片中的层流特性分隔阴阳两极取代膜材料的使用。其次，根据计算流体力学的计算模拟和MFC评价实验优化其设计。然后，将基于微流控芯片的微生物燃料电池传感器应用于生物毒性物质的定量检测，关联生物毒性物质浓度，暴露时间与响应电流的关系；探明输出电流信号对生物毒性物质的响应机制。最后结合上述两部分工作的结果对该微生物燃料电池传感器的响应性能、稳定性和精确度进行优化

微生物三电极体系（M3Cs）已经广泛地应用于生物传感和电化学活性细菌的研究上。与传统的两电极体系（微生物燃料电池和微生物电解池）相比，M3Cs能够提供稳定并且明确的电化学环境。本项目致力于研究与实验室级别（毫升级）的M3C具有相同性能的微升级M3C。在此系统中，层流被用来分隔参比电极通道与溶液本体通道，实现了在微升级别的体系中整合M3C并形成一个稳定的三电极系统的目的。通过整合的参比电极，工作电极的电势被准确地控制从而为细菌生长提供了一个稳定的电化学环境。系统运行33天之后，参比电极的电势仍然稳定在原先的水平，证明了系统的稳定性。同时利用铁氰化钾和细胞色素c的标准电极电位对系统的稳定性进行测试，结果同样显示了该系统具有良好的稳定性。利用微升级的体积和秒级的水利停留时间，实现了对柠檬酸铁、重金属、抗生素等物质的快速响应。而且电流信号响应具有良好的重现性和与化学刺激信号之间良好的线性关系。我们的研究结果表明，该项目开发的微流控三电极体系在毒性物质检测方面和产电细菌筛选方面是一种很有前景的平台。

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