Shining new light on the body
Researchers from the ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) are using Raijin to design ultrasensitive biosensors for use in research and medical diagnosis.
Led by Professor Andrew Greentree at RMIT University, the team are using computer modelling to design new devices, including ones that incorporate so-called ‘Whispering Gallery’ resonators.
“In the Whispering Gallery of St Paul’s Cathedral in London you can whisper and somebody on the other side of the dome can hear you because the sound travels around the wall,” explains Professor Greentree.
“CNBP’s Dr Jonathan Hall at the University of Adelaide is designing sensor platforms that do the same thing, but with light instead of sound.”
Whispering Gallery resonators provide a highly effective way to trap and measure light signals, says Professor Greentree.
“Light travels so fast that on a scale of a few millimetres it’s just going to zip straight past.
“But if you can trap the light in the resonator, it can bounce around inside a few million times, allowing a very small signal to be magnified and measured.”
When something comes in contact with the surface of a microbubble, it causes a blip in the resonance signal.
These sensors could be used to detect particular biomolecules of interest to understand how cells work.
The team say NCI allows them to accelerate the experimental development of these useful structures.
“Modifying all the parameters of the system using a supercomputer means experimentalists in the lab don’t have to spend time and materials recreating the entire gamut of possibilities,” says Professor Greentree.
“We are very excited to have access to NCI because the kind of modelling we are doing is just not possible without supercomputing facilities.”
The group is also looking at new types of fluorescent biomarker, such as nano-diamonds and nano-rubies, as well as ways to combine sound and light signals.
“We are also looking at the creation and detection of sound using light, which is something we are very excited about,” explains Professor Greentree.
“Conceptually it’s the same physics – light and sound kind of behave the same way, but when you try to combine, for example, ultrasound with nanoscale optics there is a big problem because of course there is a huge mismatch between the speed of sound and the speed of light.
“That means that technically it’s very hard to work out what’s going on; we need very sophisticated, very powerful computer simulations.”