Hello my name is Noushin and today I'm going to talk about something you've never heard of. Something at the intersection of science technology engineering and medicine. Something that is actually in my pocket. I'm going to talk about my research and fabricating these tiny tiny sensors. What they do. They can detect disease in human body just by analyzing human breath.
So if you blow onto my sensor it can detect the tiniest possibility of having a disease in your body but how? You know we smell different when we are sick. Our body chemistry changes when we are sick and that chemistry check is producing some chemical compounds, let’s call them biomarkers, and they go into our blood system and then into our breath and give us this unique opportunity to detect the disease just by sniffing out the breath.
But there is one big challenge here. All these biomarkers, they exist at a very low concentration down to parts per billion. How small is that? It's similar to finding one drop of dye in an Olympic sized swimming pool. Is it detectable? Yes.
Dogs have the ability to detect parts per trillion- thousand times less concentrated and that's why my research in this field starts with this. This may not be conventionally pretty but if you know how good dogs noses are you might want one of these. Dogs have 300 million olfactory receptors compared to our five million, 60 times more sensitive. In addition there inner nose has two airflow channels. One is for breathing and one is just for smelling.
Plus the dog's brain area responsible for processing this load of information is significantly larger and more sophisticated compared to humans and that's how they can easily distinguish and remember different types of things they sense around them as well as their location like a very very tuned GPS system. And it's not only specific to dogs. The honeybee antenna is a very tuned vapor sensor with a sensitivity quite comparable to dogs. You can actually train bees to smell things. The training involves giving them a couple of seconds burst of the biomarker vapour followed by sugar water reward. Then when the bees detect the scents that they are trained they stick their tongue for the sugar. So yes we can actually train dogs and bees to sniff out disease, but it's not practical which is very nanotechnology comes into play and helps us to fabricate these sensors to smell for us.
But what is nanotechnology? Nano means 10 to the power of minus 9 metres. To have a better imagination about nano this is my fingertip which is one centimetre wide and is five millimetre wide. Human hair has a diameter of 100 microns. Blood cell is about 10 micron. Bacteria is one micron. Viruses are 100 nanometres.
DNA is only 2 nanometres and these are the nano particles we produce every day in our laboratory with an average particle size of 20 nanometres. But how this can help me to fabricate supersensitive sensors is all related to the available surface area. Here we have a cube with a lens with a height of 20 centimetre now what happens to the cube surface area if I divided it into eight cubes? You'll see I'm not changing the material neither it's mass nor volume but the available surface area is doubled. Now imagine if I keep dividing each of them into smaller and smaller cubes until having cubes with 20 nanometre lens. If I do that we're going to have 10 million times larger surface area. Same material, same mass, same volume but ten million times larger surface area. In fact by shrinking the structural elements of any device down to nano scale, we are significantly increasing the available surface area for the biomarkers detection and that's exactly what I'm doing when I'm fabricating these super tiny sensors. Thank you.
6 September 2018
Interested in figuring out really, really, really small things, Noushin Nasiri is using nanotechnology to analyse your breath. She’s working on how to detect diseases before they can be detected in the blood, and she wants you to know about it.
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