'Bioeletronic Nose' Sniffs Out Water Contamination

The human nose is the inspiration behind the latest peculiarity on the water technology scene.

In a new study published by the journal Biosensors & Bioelectronics, researchers constructed a bioelectronic nose devoted to monitoring water quality. “A bioelectronic nose that mimics the human nose can detect traces of bacteria in water by smelling it, without the need for complex equipment and testing,” according to a statement from Elsevier, the publisher of the journal.

The technology may offer advantages over existing instruments. “The sensor is simple to use and it can detect tiny amounts of contamination in water, making it more sensitive than existing detection methods. The authors of the study, from Seoul National University, say this could make the technology even more useful in the field,” the statement said.

The invention employs human olfactory receptors (hOR) and single-walled carbon nanotube field-effect transistors, the study said. “For the screening of hORs which respond to these compounds, we performed CRE-luciferase assays of the two odorants in heterologous cell system,” it said.

Lead researcher Tai Hyun Park contextualized the findings.

"Water that smells bad isn't necessarily toxic," Park said. "Imagine you don't do your laundry; it's not that toxic but you don't want to wear it because the smell is bad. With drinking water, if there's off flavor, even if the water isn't toxic, you don't want to drink it. We wanted to develop a way to detect and remove this kind of contamination, so people are happy to drink water."

Traditional water quality testing can sometimes be a lengthy process. “Currently, when scientists want to know if bacteria are present in water, they have two main choices. They can take a sample to the lab, where they'll try growing the suspected bacteria in it, and then count the number of resulting colonies to determine the concentration. Or, they can analyze it using expensive lab-based gas chromatography or mass spectrometry equipment,” Gizmag reported.

Park said that this type of testing has its place in the water industry, but additional methods are needed.

"These are good ways to detect smell molecules, but they require a large amount of work before the sample is even ready to test," Park said. "And all of these tests need to be done in a laboratory with expensive equipment — they're just not suitable for the field."

This technology may have a promising future. “Once perfected and miniaturized, such technology could be used not only to detect bacteria, but also the presence of certain disease biomarkers or illicit drugs. It might additionally be utilized in the development of products such as perfume, wine and coffee, and even to establish an objective database of smells that could result in a universal ‘smell code,’” Gizmag reported.

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