A light touch: Optics in medicine and biology

Assoc Prof Paul Stoddart

Faculty of Engineering & Industrial Science, Swinburne University of Technology


Applying interdisciplinary concepts and techniques from physics (optics, mechanics) and chemistry (spectroscopy, colloids, biochemistry) to address problems in biology can have a direct impact on many of our lives.  This talk will review some of the novel ways in which we use optics, in particular, to address some of the big issues in medicine and biology.

From a physicist’s point of view, biological systems are generally quite delicate so monitoring their behaviour at a cellular level is really challenging. However, light can be well-suited to the non-destructive evaluation of these systems.

Early stage Alzheimer’s disease has no clear signs or symptoms and clinical studies have shown that sufferers can lose up to 60% of their neuronal cells before a conventional diagnosis is achieved.  However, we have recently shown that the light scattering properties of gold nanoparticles can be used for sensitive detection of trace levels of biological compounds such as the amyloid-β oligomers that have been proposed as an early stage marker of Alzheimer’s disease.  This work may lead to a significant diagnostic tool.

Cancer is another major health challenge where improvements in diagnostic methods are of significant interest.  We are developing an optical fibre sensor for enhanced endoscopic detection of tumours, based on changes in the tissue stiffness.  More generally, an improved understanding of the viscoelastic properties of tissues might help to predict and avoid other conditions, such as fluid retention in intensive care.

In another line of research, we have discovered that laser-exposed gold nanoparticles can be used to stimulate electrical activity in sensory nerves. This has exciting implications for future bionic devices such as a new generation of the bionic eye.  We are also trying to understand how this laser-evoked neural stimulation works at the membrane level.