Nanosensors

lisaped — Wed, 11 Aug 2010 08:38:37 +0000

Nanosensors, nanobiosensors, or biosensors. Nanotechnology basically deals with objects sized from 1 to 100 nanometers (which is one-billionth of a meter) in at least one dimension. Making sensors that can detect and manipulate objects of this size is technically challenging not only because of the size but more importantly because matter has very different properties at the nanoscale level. We will try to look at the WHY, WHAT, WHO and HOW of biosensors that contain, at least in one part, a nanomaterial that is crucial in its function.

Beginning with the WHY we should look at nanosensors in the context of the reasons they deserve our attention. The applications, the benefits to humankind, and necessarily, the financial benefits to the individual who devotes his talents to understanding of the technology and the economic benefits to the country that provides the infrastructure, facilities and support under which this individual can focus his or her erudition.

Think about what your sense of smell can tell you that your eyes can’t see. Noses are biosensors, able to detect small amounts of molecules invisible to the eye. For instance, you can tell if you have passed a farm or a garbage dump even if it is beyond the hill. Imagine more sensitive artificial noses that can sniff toxic chemicals, or artificial tongues that can taste the presence of poisons or pathogens in the water supply. With microfluidics and nanofluidics along with other biosensor technologies, this has become possible. Devices that can save a life, save a battalion facing chemical warfare, save an entire community whose water supply has just been contaminated by accidental plant run-off from death and disease.

lab-on-a-chip (Wyss Institute News Room)

Lab-on-a-chip is one such device. Especially with patients under critical care where there is no time to extract blood run to the lab and wait for results even with lab request is labeled “stat”, these devices could well be the factor that means life or death.

George M. Whitesides, professor at Harvard, believes in simplifying these diagnostic devices by making the following points:

- bringing down their costs in terms of production by using paper
- minimising storage requirements
- waste reduction particularly “sharps” in laboratories
- accessibility to laboratory and diagnostic tests to developing countries.
- simplification of devices to minimise or even eliminate misdiagnoses.

In a talk he gave in 2009 he described a piece of paper as small as a postage stamp that could be used to not only diagnose an illness but also to provide quantitative data for doctors. By the use of a mobile phone – a device that is ubiquitous – the patient could take a photo of the results and send this to a doctor for interpretation. (George Whitesides: A lab the size of a postage stamp 2009)

Scientific endeavor is funded by agencies and companies that can see the market potential of the research. It is therefore important to quickly look at the current market trends and how analysts are viewing the potential of current technologies in the marketplace. Market analysts predict rapid growth not only in medical nanosensor devices such as the lab-on-a-chip but other application areas as well.

Allan (2009), has identified market opportunities in:

- Printed and Large‐Area Sensors in Smart Textiles
- Low‐End Electronic Noses and Tongues
- Smart Skins
- Diabetic Test Products
- Biochips, Microarrays and Labs‐on‐a‐Chip
- Patient Monitoring and Smart Bandages
- Printed and Large‐area Sensors in Military, Intelligence and Security Markets
- Large‐Area Sensors in Environmental Monitoring
- Large‐Area Sensors in Buildings and Transportation
- Smart Packaging
- Human Enhancement and Robotics
- Pervasive Computing
- Materials and Fabrication Technology

Knowing the opportunities that exist, we can explore the science already in place and that which needs to be developed in order to obtain the funding that can enable us to pursue our scientific endeavours. The instrumentation and equipment to explore the world of the small has significant costs, such as the new facility in the NSW Node of the Australian National Fabrication Facility (ANFF) anounced in the University of New South Wales website (2010): ‘Australia’s place in the international nanotechnology market has been strengthened with the opening of a $10m, state-of-the-art nanofabrication facility at UNSW’.

The ‘National Nanotechnology Initiative’ of the U. S. government prioritizes investment in nanotechnology research and has a $1.8 billion budget for 2011 (National Nanotechnology Initiative, 2010). The Chinese have overtaken the Americans in the number of nanotechnology patents (Steenhuysen, Reuters, 2010). This is probably attributable to the heavy investment of the Chinese government in the late 1990s and the early 2000s. Nemets (2004), in his report in the China Brief says that ‘The Central government has budgeted two billion Yuan (about $240 million) for nanotech projects between 2003 and 2007; another 2 to 3 billion Yuan is due from local governments.’

The Australian Department of Innovation, Industry, Science and Research has put forward the following themes and objectives through the National Enabling Technologies Strategy :

1.   A national approach – the Strategy will work with Federal, State and Territory governments and agencies and a wide range of stakeholders, to encourage collaborative efforts and joint activities consistent with the aims of the Strategy.
2.   Balancing risk and reward – the Strategy will support the appropriate coverage of enabling technologies in policy and regulatory frameworks, and support Government agencies to ensure that Government policy is informed by an understanding of health, safety, environmental, social and economic considerations.
3.   Developing measurement capabilities – the National Measurement Institute (NMI) will develop measurement infrastructure, expertise and standards for nanotechnology and biotechnology (nanometrology and biometrology).
4.   Engaging with the public – the Strategy will increase public understanding of enabling technologies and issues surrounding them. It will also increase understanding of public concerns and aspirations about enabling technologies by technology developers and those responsible for policy formulation.
5.   Using technology for a better future – the Strategy will increase government, industry and the community’s understanding of the ways in which applications of enabling technologies may help to address major global and national challenges and increase industry productivity, and will encourage the responsible development and uptake of these technologies.
6.   Planning for the Future – The Strategy will assist government, researchers, industry and other stakeholders to prepare for the advent of new technologies by undertaking foresighting activities and supporting the development of policy and regulatory frameworks. (Department of Innovation, Industry, Science and Research, 2010)

Even without a national initiative in nanotechnology, Warris (2004) reported that Australia ranked 7th in the world (excluding the USA) in US nanotechnology patents (in 2004). He also analysed the quality and quantity of Australian scientific publications and said that ‘The percentage share of publications for each topic are within about 1 per cent of the average Australian nanotechnology share of 1.41 per cent, indicating no dramatic strengths or gaps for the topics chosen. However, the data does suggest weaknesses in soft lithography, quantum dots and semiconductor nanostructures, and a strength in biosensors.’ Warris (2004) p24.

In news closer to home, ABC Science (2010) featured an article on Dr Keiichi Torimitsu who is working with the University of Wollongong‘s Intelligent Polymer Research Institute amongst others in developing a “nano-scaled implant comprising a nano-electrode coated with an artificial membrane that mimics the receptor proteins found on the surface of brain cells”. This could be untilised for patients suffering from stroke or Parkinson’s disease.

Even closer to home, scanning through the graduate theses of the Intelligent Polymer Research Institute of the University of Wollongong, we can see that sensors are relatively frequent subject of interest: http://ipri.uow.edu.au/graduates/index.html.

Now that we have hopefully answered the WHY, we can look at the WHAT by exploring the nature of nanosensor technology, surveying the major advances that have been made, assessing the impact on society of this technology and WHO by listing who the key players are, and the HOW by reviewing the technical challenges involved in developing the technology .

References:

Images
Wyss Institute News Room, The power of innovation, JPEG, accessed 13 August 2010, http://wyss.harvard.edu/staticfiles/newsletter/newsletter-oct2009/braid_in_fingers_newsletter.jpg

Web

‘George Whitesides: A lab the size of a postage stamp’ 2009, vodcast, TED Talks, Posted Feb 2010, accessed 13 August 2010, http://www.ted.com/talks/lang/eng/george_whitesides_a_lab_the_size_of_a_postage_stamp.html

University of New South Wales, 2010, accessed 13 August 2010, ‘Nanotechnology Powers Up 2nd March 2010‘, http://www.unsw.edu.au/news/pad/articles/2010/mar/nanotech.html

National Nanotechnology Initiative, 2010, ‘Funding’, accessed 13 August 2010, http://www.nano.gov/html/about/funding.html

Nemets, A, 2004, ‘China’s Nanotech Revolution’, China Brief, Vol. 4, Iss. 16, accessed 13 August 2010, http://www.jamestown.org/single/?no_cache=1&tx_ttnews[swords]=8fd5893941d69d0be3f378576261ae3e&tx_ttnews[any_of_the_words]=nanotech&tx_ttnews[tt_news]=26719&tx_ttnews[backPid]=7&cHash=0e2e4df976

Steenhuysen, J, 2010, ‘U.S. lead in nanotech eroding, report finds’, Reuters, accessed 13 August 2010, http://www.reuters.com/article/idUSTRE62O48920100325

ABC Science, 2010, ‘Nanotechnology may tap into your mind’, accessed 16 August 2010, http://www.abc.net.au/science/articles/2010/02/25/2830261.htm

Web Reports

Allan, G 2009, ‘Large-Area and Printed Sensors Markets: 2009-2016′ excerpt, accessed 13 August 2010, http://nanomarkets.net/images/uploads/WideAreaSensorsCh1.pdf

Department of Innovation, Industry, Science and Research, 2010, National Enabling Technologies Strategy, accessed 13 August 2010, http://www.innovation.gov.au/Industry/Nanotechnology/Documents/NETS_booklet_web.pdf

Warris, C 2004, ‘Nanotechnology Benchmarking Project’, Australian Academy of Science, accessed 13 August 2010, www.science.org.au/policy/nano-report.pdf

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Secondary Sources

Nanosensors