Half adder and half subtractor logic gates based on nicking enzymes

The excellent specificity and predictability of DNA pairing and its natural ability to interact with other biomolecules make DNA an ideal material for building molecular logic devices (MLDs). However, there are still many challenges in the process of building such devices, including their complex structures, potentially harsh reaction conditions, long reaction times and so on. Thus, the parallel nature of DNA and other biomolecules needs to be developed before MLDs based on DNA can be exploited to a greater extent. In order to solve this problem, herein, we carefully selected two enzymes, Nt.BbvCI and Nb.BtsI, that were both persistent and compatible, and used them to build a nicking enzyme platform. Based on this enzyme platform, we constructed a novel XOR logic gate with flexible internal signaling. Furthermore, AND and INHIBIT logic gates were also modified to use the same enzymes as the XOR logic gate as their inputs. As a result, the algorithm process of half adder and half subtractor was realized by this work. This study provides a new approach for typical DNA-based arithmetic operations and promotes the development of advanced MLDs.