You have probably heard the latest buzzword in science – nano. Nanoscience. Nanotechnology.
It is a revolution in science which can be likened to the industrial and electronic revolution of yesteryear and more recently to the revolution brought about by the unravelling of the code for DNA, the molecule of life.
You have probably heard the latest buzzword in science – nano. Nanoscience. Nanotechnology.
It is a revolution in science which can be likened to the industrial and electronic revolution of yesteryear and more recently to the revolution brought about by the unravelling of the code for DNA, the molecule of life.
Understanding DNA brought with it a wave of hype around genetic engineering, cloning, genetically-modified foods and, unfortunately, a lot of misconceptions and headlines such as “Frankenstein foods” to rather fanciful ones such as “stay in bed and get your clone to do the work.”
Similarly, nanoscience sensationalists link this new wave to tiny little robots scuttling around your body, delivering drugs, mopping up toxins, repairing nerve cells or altering your mind, literally. That is the stuff of science fiction. What is nanotechnology and what can it do for you?
Nano is really really small. Nanoparticles are defined as particles which have at least one dimension which is between 1 and 100 nanometres. A nanometre is really a billionth of a metre.
To give you an idea, a nanometre is about thirty to fifty thousand times smaller in width than a human hair. A flu virus is about hundred nanometres, and individual atoms are in the range of a third of a nanometre. If you cannot see it with an ordinary microscope, it is either not there or most likely, a nanoparticle.
These minute particles are not new, but what has changed is that advances in scientific technology have meant that we now have the tools to be able to see, understand, manipulate, construct and use these particles. The big deal about these little particles is that they behave very differently from their large counterparts.
A good example is that of gold nanoparticles. Gold as we usually know it in jewellery is yellow. If we were to break gold apart into particles thousands of times smaller, we would have a solution of nanoparticles of gold.
The difference is immediately clear to the naked eye – instead of yellow, it’s red. By breaking the gold particles into smaller particles, we still have the same amount of gold, but instead of larger particles, we have smaller particles with a far higher surface area to volume ratio.
This alters the physical and chemical properties such as strength, stability and conductivity, creating a range of new possibilities and applications.
Now and in years to come it is expected to lead the way in diagnostics, drug delivery, alternative energy, construction, electronics, and even in space travel.
For South Africa, one of the more pressing concerns (and thus, urgent application) is in early disease detection. As with most things, the sooner a problem is detected, the sooner it can be taken care of.
So it is with your health. The sooner a doctor can detect agents which can cause disease, for example heavy metals, pesticides or other toxins, or even a virus or bacteria, the sooner you can be treated.
To have this tested on a fairly regular basis is expensive and usually involves inserting a needle into a vein in your arm to deliver a good few millilitres of blood for a battery of tests to be done.
It also means a long wait for the return of results from laboratories located elsewhere. Advances in scientific technology have now made it possible for a battery of tests to be done using just a tiny pinprick of blood, delivering results in a matter of seconds. The answer is biosensors.
A sensor is a small portable, simple device, similar to the glucose sensor (itself a biosensor) used by diabetics, which can specifically detect the levels of a compound in your body, in water and even in soil.
In the case of the glucose sensor, diabetics need to know the amount of glucose in their blood, so a molecule is attached to the sensor strip which will only detect glucose in blood.
Using sensors, we are now able to accurately detect a wide range of molecules specifically and in a very short time with applications in food, environment, human health and even in the military.
Getting results in real time from a portable and cost-effective device is of particular relevance in South Africa, where access to healthcare is limited and where many people rely on untested water for drinking.
But there is a catch. It is essential to design these biosensors so that they are as sensitive as possible, capable of detecting a minute amount of a particular compound.
The secret lies in nanotechnology. For biosensors this represents, literally, a golden opportunity. Using these nanoparticles in biosensors means that we are able to create extremely sensitive sensors able to detect molecules up to a thousand times more sensitively than before.
It could be likened to looking for and finding the needle in the proverbial haystack.
At the forefront of this wave in nanotechnology and sensors are two female scientists, Prof Tebello Nyokong (Chemistry) and myself (Biotechnology), who are currently developing the only such centre of its kind in sensors in the country.
Known as the Nanotechnology Innovation Centre in Sensors, it brings cutting edge technology to the finger-tips of the 30 PhD, Masters and Honours students now working in nanotechnology between these two research groups.
With a focus on innovation, nanotechnology means that this team can take really big dreams using really small molecules and turn that into a reality.
The NIC is being funded by the Department of Science and Technology and working with minerals giant Mintek and will be launched later this year by the Minister of Science and Technology.
Dr Janice Limson is a Senior Lecturer and runs the Biosensor Research Group in Biotechnology in the Department of Biochemistry, Microbiology and Biotechnology at Rhodes University. She is also the founder and editor-in-chief of Science in Africa magazine.
