Researchers quick to embrace 'super sensor'

By Damon Shorter

An extraordinary new chemical sensor, unveiled by Australian scientists this month, has been seized upon by ANU researchers who are already adapting the device for applications in medicine and research.

Dubbed a "nanomachine" by its inventors, the miniscule machine is so sensitive it can detect the increase in sweetness of Sydney Harbour after adding a single sugar cube, and so small that millions can fit in the palm of a hand.

Dr Ron Pace from the ANU Department of Chemistry, who devised the idea upon which the device is based, said the machine achieves its incredible sensitivity by mimicking nature.

The device can measure virtually anything that dissolves in water, Dr Pace said, including HIV viruses in a patient's blood, cancer cells, pesticide residues, pregnancy hormones, fragments of heart muscle indicating a recent heart attack, or even traces of marijuana on a driver's breath.

He said the nanomachine will revolutionise testing for virtually all known diseases, with doctors being able to conduct their own instantaneous, cheap and reliable tests in the surgery. Commercial products should be available within a few years.

The researchers, led by Dr Bruce Cornell from the Cooperative Research Centre for Molecular Engineering in Sydney, spent $27 million and took almost a decade the make the machine, with most of the research being carried out secretly until the product was commercially patented.

"Many have attempted to master this technology, but none, until now, have succeeded," said the Federal Minister for Science, Peter McGauran, during the official launch of the nanomachine at Parliament House this month.

Dr Cornell said the sensor, and other spin-off applications, could form the basis for a multi-billion dollar export industry for Australia. More than 30 patents have already been lodged to prevent the technology being exported overseas, and the device is being marketed through the group's commercial partner, the Australian Membrane and Biotechnology Research Institute, a subsiduary of Pacific Dunlop.

At the core of the device is a biological membrane attached to a gold electrode. By manipulating the composition of proteins in the membrane, the researchers can tailor the device to detect different things. When the proteins bind their targets-HIV viruses in a blood sample or sugar molecules in a sample of Sydney Harbour water, for instance-the electrical conductance of the membrane changes and this is measured by the gold electrode. The working parts of the machine are only about 1.5 millionths of a millimetre in size.

ANU researchers are now working closely with Dr Pace and the Sydney scientists on new applications for the device.

Dr Joe Altin, from the Division of Biochemistry and Molecular Biology, Faculty of Science, said the device would for the first time give scientists a flexible and robust system for studying biological membranes, which are central to many body functions.

Working with Professor Chris Parish from the John Curtin School of Medical Research and in collaboration with the Sydney scientists, Dr Altin will modify the device and use it to study proteins found on the surface of cells, many of which play a central role in diseases such as AIDS and cancer and are targetted by pharmaceutical drugs.

"We see this as a major application of the nanomachine," Dr Altin said. "Many drugs on the market work on these sorts of proteins. This technology opens up a whole new field of drug design and would allow us to screen drugs on a massive scale very quickly and cheaply."

Prof Parish said they were the only people in the world pursuing this exciting new application of the technology. A provisional patent on the technique was lodged last week.

Professor Peter Gage and Dr Angela Dulhunty, neuroscientists from the John Curtin School of Medical Research, are also working with the Sydney researchers to adapt the device to measure chemicals released by neurones in the brain.

Prof Gage said it may even be possible to attach the tiny chemical detector to a fine probe that could be inserted directly into the brain and record chemical activity of individual nerve cells.

"There will certainly be a lot of excitement if we can make it work," he said.

Dr Pace will present the first detailed scientific exposition of the new technology at the RSC on June 27 with Dr Burkhard Raguse from the CRC for Molecular Engineering in Sydney.