Electronic nanopores

Article By:

Timp, Gregory Beckman Institute, University of Illinois, Urbana, Illinois.

Last reviewed:2009

DOI:https://doi.org/10.1036/1097-8542.YB090148

Nanometer-diameter pores, known as ion channels, are vital to biology, as they are used to regulate the flow of molecules or ions through the otherwise impermeable nanometer-thick membranes that encompass and isolate cells from their environment. The pores can act like switches, opening and closing in response to chemistry through the binding of a ligand, in response to electricity associated with the membrane potential near the pore, or mechanically through deformation in the membrane. This regulatory motif has been observed in action. Modulation of the ionic current through a single nanopore associated with the salt water in the environment of a cell has been observed using a patch clamp pioneered in Nobel-prize winning work by B. Sakmann and E. Neher. A patch clamp consists of a glass micropipette filled with electrolyte that is in contact with a chlorinated silver wire conducting electricity to a low-noise amplifier. The open tip of the macropipette, which is about 1 micrometer in diameter, is sealed to a portion of a cell membrane containing a pore to record the current through it.

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