Queensland researchers are working on a diagnostic technique that can sense down to the single-molecule level.

Australian Research Council Future Fellow Professor Warwick Bowen said the research demonstrated how quantum technologies could revolutionise the study of life’s nanoscale machinery, or ‘biological motor molecules’.

“Motor molecules encode our genetic material, create the energy our cells use to function, and distribute nutrients at a sub-cellular level,” Professor Bowen said.

“Unlike methods currently available, the technique helps us observe the behaviour of single biomolecules without large-label particles or damaging light intensities.”

Motor molecules drive all of life’s primary functions, but scientists do not fully understand their workings.

The new technique should open a new door to study motor molecules in their native state, at the nanoscale.

It relies on a number of developments first created to detect gravitational waves from black holes in outer space. Picking up the unimaginably small variations in gravity created by collisions across the galaxy is now helping enhance our understanding and ability to manipulate molecular biology.

“Recently, exceptional sensitivity has been achieved using the strongly enhanced evanescent fields provided by optical microcavities and plasmonic resonators,” the paper states.

“However, at high field intensities, photodamage to the biological specimen becomes increasingly problematic.

“Here, we introduce an evanescent biosensor that operates at the fundamental precision limit due to the quantization of light. This allows a four orders of magnitude reduction in optical intensity, while maintaining state-of-the-art sensitivity.

“It enables quantum noise-limited tracking of single biomolecules as small as 3.5 nm, and monitoring of surface–molecule interactions over extended periods.”

Researchers from five countries - Australia, New Zealand, Denmark, France and Pakistan – were involved in the project, which was funded by the United States Air Force Office of Scientific Research.