A novel biohybrid electronic device architecture for environmental and physiological sensing

细菌鞭毛马达是自然界罕见的旋转分子机器之一。它使细菌能够游泳，是细菌趋化网络的关键部分，使细菌能够在给定的化学环境中指导它们的运动。这个网络是生物学中研究得最好的化学信号网络之一，在几秒的时间尺度上感应到特定化学物质的纳摩尔浓度。电机的转速与细菌的电化学梯度成线性比例，最明显的是质子或钠离子，而其方向由趋化网络调节。最近，人们发现电动机也是一种机械传感器。鉴于这些特性，该马达有潜力作为一种具有前所未有的速度和灵敏度的多模态生物传感器，从而成为表征和研究外部环境以及细菌生理学本身的工具。然而，在所需的分辨率下，电机的速度和旋转方向目前是通过光学检测的，一次检测一个电机。利用这种旋转分子机器的前所未有的潜力的一个阶梯式变化将是电检测每个电机的旋转和高通量。在这里，我建议通过将单个细菌附着在表面的精确位置来实现这一目标，并测试两种检测电机旋转的电子方法：集成电路和石墨烯表面。该检测方法还将用于充分表征鞭毛马达提供的三种不同的传感模式：细胞自身生理学、机械力和一组给定化学物质。该项目的成功将使便携式生物传感器芯片配置的电机速度和旋转方向检测成为可能，这将改变生物传感领域的游戏规则。

The Bacterial Flagellar Motor is one of nature's rare rotary molecular machines. It enables bacterial swimming and is a key part of the bacterial chemotactic network that enables bacteria to direct their movement given the chemical environment. This network is one of the best-studied chemical signalling networks in biology, sensing down to nanomolar concentrations of specific chemicals on the time scale of seconds. The motor's rotational speed is linearly proportional to the bacterial electrochemical gradients, most notably of proton or sodium ions, while its direction is regulated by the chemotactic network. Recently, it has been discovered that the motor is also a mechanosensor. Given these properties, the motor has the potential to serve as a multimodal biosensor with unprecedented speed and sensitivity, and thus a tool for characterizing and studying the external environment, but also bacterial physiology itself. However, at the resolution needed, motor speed and rotational direction are currently detected optically, one motor at a time. A step-change in harnessing the unprecedented potential of this rotary molecular machine would be to detect each motor's rotation electrically and with high throughput. Here I propose to achieve this by specifically attaching individual bacteria to a precise location on the surface and testing two electrical means of detecting the motor's rotation: an integrated circuit and a graphene surface. The detection method will also be employed to fully characterize the three different sensing modalities offered by the flagellar motor: that of cells own physiology, of mechanical forces and of a given set of chemicals. The success of the project we will enable portable biosensor-on-a-chip configuration of the motor speed and rotational direction detection, which can be a game-changer in the biosensing field.