The invention provides a binding-induced DNA nanomachine that can be activated by proteins and nucleic acids. This new type of nanomachine hamesses specific target binding to trigger assembly of separate DNA components that are otherwise unable to spontaneously assemble. Three-dimensional DNA tracks of high density are constructed on gold nanoparticles functionalized with hundreds of single-stranded oligonucleotides and tens of an affinity ligand. A DNA swing arm, free in solution, can be linked to a second affinity ligand. Binding of a target molecule to the two ligands brings the swing arm to AuNP and initiates autonomous, stepwise movement of the swing arm around the AuNP surface. The movement of the swing arm generates hundreds of oligonucleotides in response to a single binding event. The new nanomachines have several unique and advantageous features over DNA nanomachines that rely on DNA self-assembly.
