SYDNEY-A joint research effort by Australia and China has opened the door for far more advanced imaging methods by shattering the previous limits of possible optical detection depth. A University of Technology (UTS) team has achieved what they refer to as the “sweet spot,” which allows light to penetrate deeper than current X-Ray and MRI capabilities without being scattered by interference with tissue. “The deeper you penetrate tissue with light the more it is absorbed and the more it scatters, impairing the resolution,” study joint author, Fan Wang from UTS Institute for Biomedical Materials and Devices (IBMD) said. “We demonstrated that there is an optical narrow window in the near infrared (NIR) wavelength range, a sweet spot if you like, that allows light to penetrate deeper into tissue, beyond 50 nanometers (nm), which up until now, has been considered the limit of optical detection,” he said.



A nanometer is one thousand-millionth of a meter, meaning previous imaging techniques were unable to penetrate beyond the first layers of human tissue to reach vital organs.

“Having broken through the 50nm limit we demonstrated the technology at a liver, brain or kidney tissue depth of 100 microns (100,000 nm) where you could still see a single molecule which means there is the potential to detect a single disease biomarker,” Wang said.

Supported by National Natural Science Foundation of China and the China Scholarship Council, the team is one of a few groups in the world to be doing this kind of research which in the future could revolutionise how doctors diagnoze patients, making the process safer and cheaper.