Bacterial Nanofluidic Structures for Medicine and Engineering

Bacteria are microscopic, single-celled organisms that utilize a variety of nanofluidic structures. One of the best known and widely used nanofluidic structures that are derived from bacteria is the α-hemolysin pore. This pore, which self-assembles in lipid bilayers, has been used for a wide variety of sensing applications, most notably, DNA sensing. Synthetic pores drilled in a wide variety of materials, such as silicon nitride and polymers have been developed that use inspiration from the α-hemolysin pore. Higher-aspect-ratio nanofluidic structures, akin to nanotubes, are also synthesized by bacteria. Examples of such structures include those that are associated with bacterial transport apparatus, such as pili, and are used by bacteria to facilitate the transfer of genetic material from one bacterium to another. Flagella, and its associated structures, such as the rod and hook, are also tubular nanostructures, through which the protein, flagellin, travels to assemble the flagellum. Genetic engineering allows for the creation of modified bacterial nanopores and nanotubes that can be used for a variety of medical and engineering purposes. Frontispiece images reproduced with permission from References 55,8,85. Copyrights 1996, American Association for the Advancement of Scicnce, 2009, Elsevier, and 2007, Institute of Physics, respectively.