Figure 5.

Triplex-based devices capable of capturing and releasing molecules: (A) Control of a tweezer-like DX device that captures/releases single-stranded DNA. The captured strand binds through triplex formation and is subsequently held in place by the addition of toe-hold containing strand that forms the second crossover of the molecule. Upon increasing the pH, the oligonucleotide remains trapped, and is only released by removal of the toe-hold containing strand by addition of its W–C complement. Adapted from (65) with permission. (B) Control of a clamp-like device that detects ATP. A triplex generated within the molecule by the addition of its R-strand brings into close proximity two halves of a split aptamer capable of binding ATP. Adapted from (67) with permission.