Lighting up the heart of photonics

11 March 2020:

As one of the first members of the Centre for Nanoscale BioPhotonics, Professor Heike Ebendorff-Heidepriem’s work touches virtually every piece of research at the centre.

She develops the optical glass fibres, along with their crucial coatings, that deliver information about the environment they are designed to measure.

Optical fibres were invented for telecoms applications but, as Heike explains, the requirements are different for sensing.

“With optical fibres for telecom applications, you want to isolate the light guided in the fibre from the environment – they have a core surrounded by cladding, and the light is guided in the core,” says Heike, a Senior Investigator at CNBP.

“But we want light interacting with the environment.”

That can be achieved in a variety of ways. For instance, coating the tip of a fibre with a material that interacts with specific molecules to create a fluorescence as a marker for the specific molecule.

The list of applications is endless, from detecting the pH of a sample to measuring temperature in-vivo.

Heike and her team at The University of Adelaide have also developed novel fibres with an exposed core.

Heike (centre right) and her team.

“The cladding has an opening so that the core is exposed to the environment, and you can put the coating along the whole length of the fibre,” she says.

Heike came to Adelaide in 2005 when Professor Tanya Monro became inaugural chair of photonics at The University of Adelaide. She and Heike had been colleagues for about three years before that, however.

“Tanya was the best supervisor I ever had and I wanted to continue working with her,” says Heike. “Joining her in Adelaide was a once in a lifetime opportunity to build my own lab.”

“Tanya is, by training, a physicist and so we were a really great team. We were so complementary. I think this was part of our strength and why we then could build a great team, here in Adelaide,” says Heike.

While Heike’s work at CNBP involves engineering and physics, her roots are in chemistry, in which she earned her PhD from the University of Jena, Germany in 1994.

In addition to working with engineers and physicists, Heike also teams up with chemists and biologists to solve real-world problems.

She cites Dr Jiawen Li’s tiny fibre-optic probe – which is both a temperature sensor and imaging device – as an example of the success that can only come from working together with people from across disciplines.

The ultra-thin probe has potential to measure a variety of biological processes in a minimally invasive way, from pH levels to the accumulation of plaque in arteries.

An optical fibre uses light for real time measurements.

The fibre-optic probe, which Li developed with CNBP’s Professor Robert McLaughlin and Dr Erik Schartner, includes a tellurite glass coating which utilised a special tellurite glass developed by Heike’s team several years ago.

“Erik developed the coating of a fibre tip with this glass so that it could do temperature sensing,” Heike explains.

“It’s a great example of the Centre having people with very different expertise and bringing it all together.”

While her work is in the experimental realm, she is motivated by the potential to make a difference in the everyday world

“It’s the applications that truly excite me,” she says.

“If we can make sensors that can be used by clinicians to measure things they couldn’t sense beforehand it could revolutionise medical practice.”

She points out that one major challenge is finding a way to measure chronic pain objectively, which would help clinicians prescribe the right medication or therapy.

“We are working towards these solutions,” says Heike. “Everybody, of course, would like to have them within three or five years to have, but I’m realistic, it takes 10 to 20 years.”

One thing she’s certain of is there will never be a shortage of things to measure.

“Once you find the right biomarkers, you can find a way to measure it,” says Heike.

“That’s what keeps me going when I face challenges. I think of the things that we can potentially do in the future.”