DNA logic gates take biomolecules (e.g., DNA) or other external information as input and characterization results induced by the changes of DNA structures as output. After Boolean operations, the mutual identification and correlation of various inputs can be determined. In addition, multiple cascaded logic gates, or logic circuits, can be constructed by taking the output of the former logic gate as the input of the latter one. With the various combination and different output modes, logic circuits enjoy broad biomedical application prospects.

Recently, MIAO Peng's group from the Suzhou Institute of Biomedical Engineering and Technology (SIBET) of the Chinese Academy of Sciences has developed a novel bipedal DNA walking nanomachine, the researchers constructed a series of DNA logic circuits based on cascade strand displacement amplification. The tools can be used to explore relationships between biological molecules in complex samples.

In this research, track DNA probes with the stem-loop structure were modified on the electrode interface. In the upstream homogeneous system, target-triggered strand displacement amplification was introduced to generate a large number of single-stranded sequences.