Recent advances in molecular machines based on toehold-mediated strand displacement reaction

Background: The DNA strand displacement reaction, which uses flexible and programmable DNA molecules as reaction components, is the basis of dynamic DNA nanotechnology, and has been widely used in the design of complex autonomous behaviors.Results: In this review, we first briefly introduce the concept of toehold-mediated strand displacement reaction and its kinetics regulation in pure solution. Thereafter, we review the recent progresses in DNA complex circuit, the assembly of AuNPs driven by DNA molecular machines, and the detection of single nucleotide polymorphism(SNP) using DNA toehold exchange probes in pure solution and in interface state. Lastly, the applications of toehold-mediated strand displacement in the genetic regulation and silencing through combining gene circuit with RNA interference systems are reviewed.Conclusions: The toehold-mediated strand displacement reaction makes DNA an excellent material for the fabrication of molecular machines and complex circuit, and may potentially be used in the disease diagnosis and the regulation of gene silencing in the near future.