Major breakthrough related to the detection of nanoparticles

This text is part of the special Research section

A new system using lasers and artificial intelligence makes the invisible visible. Developed by a research team at McGill University, it makes it possible to track in real time the size, shape and transformations of tiny particles in three-dimensional space, such as the propagation of contaminants in the water.

The Nano-DIHM online digital holographic microscope includes a visible laser whose performance is improved thanks to artificial intelligence and certain optical modifications. “It makes it possible to look in an unprecedented way and in their four dimensions at particles from one nanometer to one centimeter, such as viruses, microplastics or mercury. That’s why our international colleagues called it groundbreaking,” says Parisa Ariya, a professor in the Department of Chemistry and the Department of Atmospheric and Oceanic Sciences at McGill University, who originally led this team of researchers. of this discovery.

Their determination to improve particle observation acuity was born during the pandemic. “We wanted to find solutions to detect in real time and in situ viruses in the air, but also in water, says Parisa Ariya. Our system integrating an intelligent laser makes this information available in a few milliseconds,” she describes. In other words, in the blink of an eye.

Use in many areas

The possibilities of using the new online microscope are all the more dizzying as it can collect data at a distance of thousands of kilometres. Moreover, it could one day be installed on satellites, predicts Parisa Ariya. One could therefore detect in real time pollutants of a nanometer to a centimeter (for example, particles containing mercury or petroleum) in water supply networks around the world.

Designed in response to the pandemic, this system could help manage other health threats. “The World Health Organization predicts that there will be more pandemics due to climate change. If our system is adopted by several countries, it will allow them to immediately detect viruses that spread in water and in the air and to exchange this data very easily between them”, anticipates the professor. The potential of the invention includes other very varied fields, such as the control of air quality, the exploration of the complex physical and chemical processes of aerosols or the detection and monitoring of cancer, to name a few. cite just a few.

Easy handling and low cost

The use of the Nano-DIHM microscope in oncology, with certain modifications, could improve and facilitate prevention and patient monitoring. “In the future, it will be possible to use it in association with X-rays, ultrasounds or magnetic resonance images. Some of these technologies use magnetic nanoparticles to find tumours, but they cannot directly detect those measured in nanometers, unlike our system which is non-invasive and free of harmful radiation with visible light. It also makes it possible to follow their growth, because we do not only see their three-dimensional size, but also their changes in configuration, surface, topography, etc. “, says Parisa Ariya, who would like to deepen this area.

Another advantage of the system is its very low cost, since the visible laser used is quite common. “We have broken the belief that you can’t find the diffraction barrier without a particularly powerful laser or fixing particles optically”, underlines the professor. By leading two chapters of the United Nations Environment Program on the transformation of metals in the environment, she noted the unwillingness of industrialists and governments to put their hands in their pockets to bring about major changes. “I told myself that I had to find solutions that cost nothing to help the planet,” she recalls.

The one who combines her pragmatism with the search for meaning experiences “a great pleasure in exploring, learning, but also contributing to improvements on the international level” and talking about her profession to young women. “When I was younger, I didn’t need a model, because I knew what I wanted,” she recalls. But there are still few women in physico-chemical sciences, and it’s important to open the door for others and show what we can do. »

This special content was produced by the Special Publications team of the Duty, relating to marketing. The drafting of Duty did not take part.

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