Nucleic acids have many features that are ideal for molecular computation. Using nucleic acids, we have constructed a full set of molecular logic gates, with modular stem-loop-controlled deoxyribozymes as switches and single-stranded oligonucleotides as inputs and outputs. These gates have been combined to form basic computational circuits, including a half- and a full-adder, and can also be assembled into automata to perform complex computational tasks such as game playing. Our most advanced automaton to-date integrates more than 100 nucleic acid logic gates to play a complete game of tic-tac-toe encompassing 76 possible game plays. Inputs and outputs can also be coupled with upstream and downstream components, such as aptamers, sensors, secondary gate activation, and small-molecule release, indicating the potential for nucleic acid computation in the engineering of autonomous therapeutic and diagnostic molecular devices.
Functional Nucleic Acids for Analytical Applications: Integrated Analytical Systems / Li Yingu and Lu Yi (eds): Part 3, pp.355-375