The switch is fabricated using the method of DNA self-assembly, which is sometimes referred to as DNA origami. This takes advantage of the specific and reliable pairing between complementary bases to localize structures with sub-nanometer accuracy using standard test tube chemistry.

Easy and accessible approach

By mixing a long piece of single-stranded DNA with a carefully designed soup of short DNA oligomers, a looped single-molecule linker with an integrated receptor–ligand pair is self-assembled. Significantly, this approach is easy and accessible, requiring minimal time and equipment.

This breakthrough enables new and more reliable studies of biomolecular structure and function at the single-molecule level. Experiments show that this force-switchable molecule improves single molecule experiments by providing a tunable molecular "signature" to filter out spurious data. Furthermore, the force-switching behaviour of the linker is reversible, enabling repeated measurement of binding and unbinding of a single pair of molecules, paving the way for measurements of on-rates and population heterogeneity.

Next, the team plans to use these molecular constructs with its recently developed centrifuge force microscope (CFM) to perform high-throughput studies of antibody interactions.

This new approach will enable insights into how force affects single-molecule mechanics and dynamics, including enzymatic activity, binding of receptor-ligand pairs and drug interactions.

Further information can be found in the journal Nanotechnology.