Engineered voltage-responsive nanopores.

The creation of synthetic devices that mimic functionality of biological systems is a task of fundamental importance for the future development of bio- and nanotechnology and also an ultimate test of our understanding of the biological systems. Among a plethora of bio-inspired devices, designed nanopores and nanochannels with an embedded functionality are of particular interest because of their potential applications in nanofluidic electronics, biosensing, separation, synthetic biology, and single-molecule manipulation. In this respect, nanopores with built-in stimulus-responsive properties are of special benefit. A transmembrane potential is a particularly useful stimulus as it is non-invasive, tunable, and can act over a short time scale. This critical review considers engineered solid-state and protein nanopores with voltage-responsive properties. The engineered systems show nonlinear current-voltage curves, and/or voltage-dependent switching between discrete conductance states (141 references).