Implementation of half adder and half subtractor with a simple and universal DNA-based platform

As a powerful material, DNA presents great advantages in the fabrication of molecular devices and higher-order logic circuits. Herein, by making use of the hybridization and displacement of DNA strands, as well as the formation and dissociation of a G-quadruplex, a simple and universal DNA-based platform is developed to implement half-adder and half-subtractor arithmetic processes. The novel feature of the designed system is that the two required logic gates for the half adder (an AND and an XOR logic gate integrated in parallel) or the half subtractor (an XOR and an INHIBIT logic gate integrated in parallel) are achieved simultaneously with the same platform and are triggered by the same set of inputs. Another novel feature is that the developed half adder and half subtractor are operated by the same DNA platform in an enzyme-free system and share a constant threshold setpoint. These investigations provide a new route towards prototypical DNA-based arithmetic operations and promote the development of advanced logic circuits.