Magnetotactic bacteria as dispatched oxygen sensors

MC-1 Magnetotactic bacteria are considered as self-propelled oxygen sensors with overall sizes of only 1 to 2 μm across. Each cell contains a chain of magnetite nanoparticles that acts like a magnetic nano-compass. Magnetotaxis directional control can be applied from a weak magnetic field to force each cell towards specific areas where oxygen gradient is present. Once at the region under investigation, the directional magnetic field can be reduced to allow the cells to move towards regions of 0.5% oxygen level. A sufficiently high concentration of these cells allows us to visualize with the naked eyes, the low oxygen levels in planar and 3D fluidic environments.