Chemical noses could sniff out pollutants

Once industrial pollutants get airborne or leak into water sources, it’s pretty darn hard to get rid of them. The solution then is to stop them at their sources. How to do that, though?

One way could be to have chemical noses sniffing out pollutants.

A group of researchers at the School of Science at Tallinn University of Technology in Estonia has been building a new generation of receptor molecules that can detect pesticides and other industrial pollutants that are hazardous to the environment. Such smart “electronic-nose-devices,” they say, could alert us to the presence of harmful toxins so they could be identified and removed before they are released into the environment.

“Dealing with pollutants in the environment is becoming an ever-increasing problem,” observes Professor Riina Aav, who leads the group specializing in supramolecular chemistry. “One relatively unknown reason for this is that many agricultural pesticides and pharmaceutical drugs that enter the environment are ‘chiral’, which means they exist in two non-superimposable forms (like left and right hands),” she explains.

“This molecular quirk makes it difficult for the pollution control technologies to identify and remove many of these pollutants and this cannot be achieved by traditional methods for analysis,” Aav adds.

Chirality, a certain geometric property of some molecules, can impact the environment into which the substances that contain them are released. “Chiral pollutants are found in pesticides, herbicides, fungicides, freon substitutes, dyes, antibiotics and many other drugs,” the researchers note. “In most cases we have no idea about their environmental impact.”

Work is now underway to engineer molecules that can act as receptors so that they can recognize specific pollutants. That done, the receptors could then be integrated with nanostructures to create devices that can be deployed widely to detect and destroy specific pollutants in the environment.

“These devices will function as ‘chemical noses’ by sniffing out the specific industrial pollutants, thus facilitating their removal and destruction,” the researchers say. Their aim is to build chiral molecular systems that can identify and flag specific pollutants, such as by changing their colors.

Once these systems become operational in coming years, they could help us stop pollutants at their source.