Practical design of the XOR gate is an important milestone in the field of DNA computing. In this study, we aim to develop an enzyme-free XOR gate driven by a toehold-mediated strand displacement mechanism possessing the true detection property. The advantages of our design are as follows: dual-rail logic is not required, the explicit use of the NOT gate is avoided, the circuit structure is simple, and the design is achievable with fewer DNA strands than that designed by the combination of four NAND gates. A rational circuit design is performed and the dynamic behaviors of the biochemical reaction and the secondary structures of DNA strands are confirmed by computer simulation. In particular, both the domain-level design technique with G-T mismatched base pairs and base sequence-level fine-tuning are successfully achieved to alleviate the performance degradation arising from unintended and leaky reactions present in the circuit. The validity of the XOR gate design is confirmed by experimental studies.

中文翻译：

---

面向 DNA 计算的实用完整集的异或门设计

XOR门的实用设计是DNA计算领域的一个重要里程碑。在这项研究中，我们的目标是开发一种由具有真正检测特性的立足点介导的链置换机制驱动的无酶异或门。我们设计的优点是：不需要双轨逻辑，避免了非门的显式使用，电路结构简单，设计的DNA链比四合一的设计要少。与非门。进行合理的电路设计，并通过计算机模拟确认生化反应的动态行为和 DNA 链的二级结构。特别是，GT 不匹配碱基对的域级设计技术和碱基序列级微调都成功实现，以减轻由于电路中存在的意外和泄漏反应引起的性能下降。实验研究证实了异或门设计的有效性。