Autocatalytic DNA circuitries.

Autocatalysis, a self-sustained replication process where at least one of the products functions as a catalyst, plays a pivotal role in life's evolution, from genome duplication to the emergence of autocatalytic subnetworks in cell division and metabolism. Leveraging their programmability, controllability, and rich functionalities, DNA molecules have become a cornerstone for engineering autocatalytic circuits, driving diverse technological applications. In this tutorial review, we offer a comprehensive survey of recent advances in engineering autocatalytic DNA circuits and their practical implementations. We delve into the fundamental principles underlying the construction of these circuits, highlighting their reliance on DNAzyme biocatalysis, enzymatic catalysis, and dynamic hybridization assembly. The discussed autocatalytic DNA circuitry techniques have revolutionized ultrasensitive sensing of biologically significant molecules, encompassing genomic DNAs, RNAs, viruses, and proteins. Furthermore, the amplicons produced by these circuits serve as building blocks for higher-order DNA nanostructures, facilitating biomimetic behaviors such as high-performance intracellular bioimaging and precise algorithmic assembly. We summarize these applications and extensively address the current challenges, potential solutions, and future trajectories of autocatalytic DNA circuits. This review promises novel insights into the advancement and practical utilization of autocatalytic DNA circuits across bioanalysis, biomedicine, and biomimetics.