Two strands of DNA
will bind most strongly to each other if their base sequences are
complementary. The specificity of this molecular recognition
property makes DNA a versatile material for use in the assembly of
complex nanoscructures. The free energy of hybridization,
released as two DNA strands come together to from double-stranded DNA,
can be used to induce nanostructures to perform mechanical work.
Strand displacement allows one to operate such structures as cyclic
engines. DNA can thus be used both as a structural material and
as a fuel to power the nanoworld.