Sensor stripped for speed
NanoBang™ could determine the strength of
a heart attack with the speed and simplicity of
a pregnancy test.

The human body is a network of many diverse and specialised systems, ideally all functioning cooperatively and effectively like a well-maintained machine. But it is external machines and devices that are relied on more and more to restore the body’s health when serious illness strikes.

New technology that could lead to a device capable of determining the severity of a heart attack and the most effective response – with the speed and simplicity of a home pregnancy test – has been developed.

A multidisciplinary research team at CSIRO Industrial Physics (CIP) has developed a ‘quantitative lateral flow’ technique that exploits the unusual properties of nanomaterials, creating a novel and simple-to-use sensing device.

One of the new NanoBang™ test devices uses light and heat absorption, and the way nanoparticles heat up more than bulk materials, to create an acoustic signal. This signal can be used to detect an analyte – the chemical to be analysed. Like pregnancy test strips, NanoBang™ diagnostic devices are ‘immunochromatigraphic’ test strips, using a commonly used immunological technique in which the analyte is captured by one protein and detected by another.

Inventors of the technology, Dr Burkhard Raguse and Lech Wieczorek, say they found a way of easily and cheaply turning the colour-response signal seen on the test strip into an acoustic signature, then converting it to an electronic signal.

“We zap the lateral-flow test strips with light, causing the nanoparticles to absorb the light and generate an acoustic response, which can be measured and integrated,” Dr Raguse says. “The integration gives a signal that directly relates to the number of particles captured by the proteins.”

Dr Scott Martin, leader of the Manufactured Devices research theme at CSIRO, explains that the research team was in a unique position to identify a gap in technology that marketers of lateral-flow tests have wanted to fill for decades, and to devise a successful answer.

 “There is a lot of interest in quantification – for applications where the existing tests require a visual assessment of a response to give a high, medium or low reading,” Dr Martin explains. “It’s highly desirable for such diagnostics to be quantitative and to have an instrument to accurately tell you ‘how much’. NanoBang™ has the best of both worlds – the speed of a lateral-flow device and the quantitative output of a pathology lab test.”

By addressing this market opportunity, scientists at CSIRO now hope to make a splash in the commercial market.

Dr Martin says there are a number of Australian manufacturers of lateral-flow devices, and that company location and size are not critical to market success. “Australia already contributes very strongly to the global medical device market, with significant manufacturing taking place here and with superior exports,” he says.

The current market for lateral-flow devices is estimated at US$2.1 billion.

“CSIRO has a background in dealing with biological systems, biophysics, and chemical and biosensors,” Dr Martin says. “Practical and theoretical knowledge of how these nanocomposites work has allowed a novel solution to an enduring problem; a solution that is competitive on both cost and performance.”

The technology behind NanoBang™ devices is not limited to medical diagnostics, and has wide potential for use in agriculture, veterinary practices and environmental applications. “We expect this technology to be useful for monitoring pesticides, water quality and animal health,” Dr Martin says. “It is applicable to a wide variety of areas, creating an opportunity for a broad range of commercial partners.”

Speedy quantification is not the only scientific hallmark of CSIRO’s new sensing technologies based on properties of nanotechnologies and biomimetics. Dr Raguse says that while many of the currently used techniques are suitable for measuring molecular interactions, real-world samples contain many other constituents than the molecule of interest, creating complications.

“There is a lot of background contamination of other materials, which complicates detecting the analyte. A lot of these technologies work in the laboratory, but they don’t translate to real-world samples. We are trying to develop technologies that are very cheap and simple to produce in an Australian context, and different from the norm, to get around some of the issues such as selectivity, sensitivity and non-specific binding.”

The team has completed the proof-of-concept phase for the technology, and is now preparing to find commercial partners. “We are engineering the technology into an alpha prototype for testing. Within the next year we expect to get it to a stage where it can be offered to people for testing in various applications. In doing that, we hope to identify the key opportunity areas for the technology, and ultimately be in negotiations with commercial partners by mid-2008.”

Editor's Note: First published in issue 12 (August 2007) of CSIRO's SOLVE. For permission to republish this article please contact SOLVE.