Richard Martel and his research team at the Department of Chemistry of the Universit de Montral have discovered a method to improve detection of the infinitely small. Their discovery is presented in the November 24 online edition of the journal Nature Photonics.
"Raman scattering provides information on the ways molecules vibrate, which is equivalent to taking their fingerprint. It's a bit like a bar code," said the internationally renowned professor. "Raman signals are specific for each molecule and thus useful in identifying these molecules."
Applications of the discovery: retail, banks, hospitals, etc.
The discovery by Martel's team is that Raman scattering of dye-nanotube particles is so large that a single particle of this type can be located and identified. All one needs is an optical scanner capable of detecting this particle, much like a fingerprint.
"By incorporating these nanoparticles in an object, you can make it perfectly traceable," he said. Due to their unique structure, carbon nanotubes, which are electrically conductive, can be used as containers for various molecules. Coupled with a dye, these nanoprobes can increase the complexity and strength of the received signal.
Nanoprobes, which are composed of around one hundred dye molecules aligned inside a cylinder, are 50,000 times smaller than a human hair.
They are about one nanometre (nm) in diameter and 500 nm long, yet they send a Raman signal one million times stronger than the other molecules in the surrounding.
According to Professor Martel, the applications from this discovery are numerous. In medicine, nanoprobes could lead to improved diagnostics and better treatment by adhering to the surface of diseased cells. These specifically modified nanoprobes could, in effect, be grafted to bacteria or even proteins, allowing them to be easily identified.
One could also imagine custom officers scanning our passports with Raman multispectral mode (i.e.
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University of Montreal