Nanosensors supported studies of bacterial evolution

为了以自动化的方式研究细菌中抗生素耐药性的发生，本项目旨在设计、测试和应用一种将基于微滴的微流体与基于纳米线的离子传感器相结合的芯片设备。虽然基于微流体的微流体允许最大程度地并行测量细菌分离物的进化（在任何给定时间多达104个实验），但基于纳米线的离子敏感检测可以通过记录pH值变化和碳源消耗的独特时移曲线来探测细菌的代谢活性和活力。后一种信息，目前的方法无法获得，为微生物分析领域带来了一个新的维度，因为没有光学可检测的生长并不一定意味着细胞死亡和/或不消耗/产生特定的化学物质。最重要的是，对数千个液滴进行多步骤和高度并行的处理（孵育、分选、用新鲜营养物重新喂养），包括对下一轮抗生素浓度具有更高耐药性的物种的自动转移，将能够以高复制率和早期发现突变种群来完成完整的“进化周期”。随着这一发展，我们回答了一个问题，即电子小型化生物传感器系统是否可以作为观察细菌进化过程的有效工具。

To study the occurrence of antibiotic resistance in bacteria in an automated fashion, this project aims to design, test and apply an chip device by combining droplet-based microfluidics with nanowire-based ion-sensorics. While droplet-based microfluidics allows for maximally parallelized measurements on the evolution of bacterial isolates (up to 104 experiments at any given time), nanowire-based ion-sensitive detection enables probing the metabolic activity and viability of bacteria, by recording unique time-lapse profiles of changes in pH and carbon source consumption. The latter information, not accessed by current methods, brings a new dimension into the field of microbiological analysis, because the absence of optically-detectable growth does not necessarily mean the cells are dead and/or do not consume/produce specific chemicals. Most importantly, the multistep and highly-parallel treatment of thousands of droplets (incubation, sorting, refeeding with fresh nutrients) including the automated transfer of species with increased resistance to the next round of antibiotic concentrations, will enable to close the full “evolution cycle” at high replication rates and early detection of mutant populations. With this development, we answer the question, whether the electronic miniaturized biosensor system could act as a valid tool for the observation of the evolutional processes in bacteria.