Interlocked DNA nano-joints for reversible thermal sensing.

The ability to precisely measure and monitor temperature at high resolution at the nanoscale is an important task for better understanding the thermodynamic properties of functional entities at the nanoscale in complex systems, or at the level of a single cell. However, the development of high-resolution and robust thermal nano-sensors is challenging. Here we describe the design, assembly and characterization of a group of thermal-responsive DNA-joints which consist of two interlocked double-stranded DNA (dsDNA) rings. The described DNA nano-joint can reversibly switch between the static and mobile state at different temperatures without a special annealing process. The temperature response range of the DNA nano-joint can be easily tuned by changing the length or the sequence of the hybridized region in its structure, and due to its interlocked structure, the temperature response range of the DNA nano-joint is largely unaffected by its own concentration, which is different from systems that consist of separated components.