Without needing complex equipment for testing, traces of bacteria in water can now be detected using a bio-electric nose by just smelling it.
The sensor is simple to use and it can detect tiny amounts of contamination in water, making it more sensitive than existing detection methods. This human-like nose can be used to detect drugs at airports, test food quality and develop perfumes.
Water that smells bad is not necessarily toxic, like a bad-smelling shirt which has not been washed.
"We wanted to develop a way to detect and remove this kind of contamination, so people are happy to drink water," said professor Tai Hyun Park from from Seoul National University who led the research.
Traditionally, water was tested for contamination with bacteria by taking a sample and trying to grow the bacteria in the lab with large scientific equipments such as gas chromatography or mass spectroscopy.
The new study shows how technology that mimics the human nose can sniff out low levels of bacteria and other microbes by detecting the off flavor they give off. The new nose-like device can detect smells at very low concentrations of just 10 nanogram per litre of water. It is also very sensitive and can spot a particular smell in a cloud of others.
"Our eventual goal is to develop a real human nose-like bioelectronic nose," Park added. In the human nose, there are about 400 different olfactory receptors. "If we could develop our technology to include all of these, we would have a device that could smell anything we can, at lower concentrations," the authors noted.
A smelling device could be very useful for the smell industry, such as perfume, cosmetics, wine and coffee. Certain diseases, such as lung cancer, can cause patients to give off particular smells. There is also a role for security, for example in drug searches at airports.
The study was published in the journal Biosensors and Bioelectronics