A contractile electronic switch made of DNA.
Double-helical DNA has been shown to conduct both electrons and electron holes, the latter over distances of >20 nm. DNA is thus a material of significant interest for the bottom-up construction of nanocircuitry. Here, we describe a contractile DNA nanoswitch, which can toggle between a structurally extended "off" state and a contracted "on" state, with a 40-fold conductivity difference between the two. To turn on, two short motifs of guanine-guanine mismatches in an otherwise standard double helix synapse to form a conductive G-quadruplex, bypassing an insulating element within the helix. This switch can be turned repeatedly on by treatment with millimolar concentrations of K(+) and turned off by sequestration of the K(+) by a crown ether. Circular dichroism and thymine-thymine photocross-linking experiments reveal that strand orientations within the on state G-quadruplex are wholly antiparallel and that the two conductive double-helices interface with the same face of the quadruplex. Although this DNA nanoswitch is chemically gated, it should be adaptable to other kinds of gating and thus serve as a prototype for increasingly sophisticated and complex electronic devices made of DNA.
Huang
Yu Chuan
YC
Department of Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
Sen
Dipankar
D
D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004581:Electronics / Q000295:instrumentation; D004583:Electrons; D054856:G-Quadruplexes; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation
D004247:DNA