Engineering chemical reaction modules via programming the assembly of DNA hairpins

The architect of enzyme-free chemical reaction modules, working as building blocks in implementing complex computing tasks, was achieved by modulating the assembly of DNA hairpins, including noncatalytic and catalytic systems. The performance of heterogeneous outputted sequences, which were programmed on different hairpins for triggering the downstream reaction, was asymmetric in the noncatalytic system, whereas symmetric in the catalytic system. Furthermore, complicated DNA-only chemical modules possessing controllable species of inputs or outputs were constructed based on our strategy. The kinetic studies revealed that the performance of the chemical modules was toehold length correlated; on the basis of which, a DNA concentration monitor was constructed.