Small science, big idea

Report: Martin Curtis
Photography: Andrew Curtis

Monash scientists are poised to commercially release the world's first biosensor to detect chemicals that can make water toxic. The pen-sized device has been developed by analytical and environmental chemists based at the Gippsland campus of Monash University.

The predicted impacts of climate change are set to place pressure not only on the amount of water available to industry, households and the environment, but just as importantly on the quality of water available.

Professor Sam Adeloju

Professor Sam Adeloju is the head of Applied Sciences and Engineering at Gippsland and has warned more extreme weather events could lead to more flooding and cases of water contamination, restricting the use of critical water storages.

"In Victoria we've now had 11 years of drought which is having significant impacts already in some areas," Professor Adeloju said. "We are therefore at a critical point where we cannot afford to lose scarce water resources to pollution."

Water bodies such as the Gippsland Lakes are a good example of a resource under threat, vulnerable to blue-green algal breakouts due to a combination of water runoff from farms containing phosphates and nitrates, and the shallow, enclosed waters of the lake system. Past algal outbreaks have led to large numbers of fish deaths and the lakes being closed to stock and humans due to the risks of toxicity.

Professor Adeloju's team has developed a new nanobiosensor for water authorities to closely and accurately monitor water health after flooding or heavy rain.

Portable, highly-sensitive, reusable and low cost, they will be among the world's first commercialised nanobiosensors and could change the way water monitoring is carried out in Australia and around the world.

Water samples have traditionally been collected and sent to laboratories for testing for nitrate and phosphate. The whole process can take days, even weeks, before complete analytical data is available, particularly if the samples are taken from remote areas or a large number of samples are involved.

The nanobiosensor gives an instant and accurate read out of phosphate and nitrate levels down to parts per billion, allowing water authorities to make public health decisions immediately if there is a threat.

"Being able to measure nutrient and salinity levels immediately after flooding will be extremely important in providing rapid responses and achieve more sustainable water management practices and clean water supplies in the future," Professor Adeloju said.

The biosensor has been developed with assistance from Nanotechnology Victoria. It can also detect sulfites, which some people are allergic to, in food and drink.

Design of the active component of the biosensor has involved the use of nanotechnology in two distinct dimensions. Firstly, through incorporation of nanoparticles to improve robustness and sensitivity of the biosensors. Secondly, through the use of nanolayers (ultra-thin layers) of a conducting polymer to trap bioactive components that target phosphate, nitrate and sulfite.

"The biosensor mimics some of the biochemical processes that occur in nature. So if we are trying to detect glucose in human blood, for diabetes for example, we use an enzyme called glucose oxidase to detect it. We use sulfite oxidase to detect sulfite and so on.

"Once we have identified the right enzymes for a particular substance we want to detect, we then wrap the polymer nanolayer around the enzyme and the nanoparticles, embedding them in the skin of the polymer so that they can be used successfully for rapid detection of the substance."

Professor Adeloju said issues of regulation of nanotechnology were important and he supported efforts at Monash University and elsewhere to prompt discussion about how developments in the science of nanotechnology were best monitored and regulated.

Professor Sam Adeloju

Regulation of nanotechnology

Senior staff from the Monash Faculty of Law have called for a wide-ranging debate about the nature and extent of regulation of the emerging area of nanotechnology.

It is estimated between 500 and 700 commercially available products have been developed using nanoscience. Some predictions are that the industry will have an economic value of US$1 trillion by 2015.

Products already include some cosmetics, sunscreens and foods, plus sporting goods and clothes that resist stains.

Scientists working for the US Air Force have produced T-shirts and underwear that can be worn for weeks at a time without washing. Other products in development are self-cleaning bathroom surfaces and lighter, but stronger, metals in the motor industry.

Three researchers from the Monash Centre for Regulatory Studies warn there are concerns in the scientific and legal communities that nanoscience developments are proceeding outside a regulatory framework.

Professor Graeme Hodge, Dr Karinne Ludlow and Ms Diana Bowman write in the introduction to New Global Frontiers in Regulati on that "while this emerging family of technologies offers numerous promises and benefits, an opportunity also exists, as with all technologies, for significant social, political and scientific problems to emerge.

"At present, nanotechnology is challenging scientists, governments, regulatory bodies, governance and regulatory scholars alike. It is therefore crucial that governments learn from the development of previous technologies and products, such as GMOs (Genetically Modified Organisms) and asbestos, and adopt an integrated approach to the regulation of this emerging technology."

The authors propose several regulatory models for the area and call for a robust debate at government and community level.