Highly Reusable Enzyme-Driven DNA Logic Circuits

In recent years, DNA has emerged as a promising molecule for the construction of molecular computing systems. In the research field of DNA logic circuits, enzyme-driven DNA logic circuits, which offer faster reactions and lower complexity, have become the key focus in the field. However, it remains a significant drawback that it lacks the capability of being reused. Reusability is essential to enhance the computational capacity, correct errors, and reduce costs in DNA circuits. In this study, we propose a method for achieving high reuse in enzyme-driven DNA logic circuits using exonuclease III. By selectively digesting ds-DNA while preserving gate strands, our system highly restores the circuit to its initial state, which contains no waste-strand. This reuse method has demonstrated good performance in the converted-input reuse experiment of single-gate, multilayer cascades. Finally, we achieve four times converted-input reuse in a relatively complex circuit and three times multiple reuse in a square root DNA circuit.