Nanoparticle Sniffing Nose to Fight Cancer

Why let those dogs get all the press? A group at University of Massachusetts Amherst led by Dr Vincent Rotello and Uwe Bunz of the Georgia Institute of Technology has created a nanoparticle sensing “nose” whose mode of operation is modeled after the way your nose works…

Rotello’s team wanted to design a detection method that operated more holistically, like the human nose, which uses a combination of receptors to interpret and identify smells. A protein that was exposed to this molecular nose would stimulate a group of sensing receptors in a signature pattern that could be read like a fingerprint. Unknown or new proteins would have a unique signature as well and could be identified with much less effort than standard techniques.
So the scientists set out to build a molecular nose using gold nanoparticles, materials that can be precisely manipulated into a variety of shapes and sizes. They added a florescent dye to their sensors, so they could see which ones were interacting with a particular protein. All proteins have a unique shape–one might have sections with an electrical charge, for example, or particular kind of chemical bond. Depending on its shape each protein stimulates only certain sensors to release dye and glow, the intensity of the glow varies with protein shape as well. With a computer’s assistance, the researchers can then read the glow pattern like a fingerprint and identify the protein that’s present.
Rotello’s team used six different kinds of nanoparticles to sense for seven different proteins, some of which were intentionally very similar. Ninety-four percent of the time the sensors correctly identified the given protein. The scientists also worked out a technique for dealing with varying protein concentrations, which can sometimes confuse analyses. And by combining their raw data with statistical analyses, the researchers were able to correctly identify 56 randomly selected proteins with 96 percent accuracy.
The chemical nose approach provides a distinct method of sensing that has the potential to be more reliable (fewer false negatives and false positives) and cheaper than current technology, says Rotello. The research team is currently focusing on sensors for detecting the malformed proteins produced by cancer cells, but the technique holds promise as a means for detecting a wide variety of diseases, he says.

The work can be found in the May issue of Nature Nanotechnology (abstract).
Press release: UMass Amherst Scientists Create Nano Nose With Aim of Sniffing Out Diseased Cells …