World first 'super twisted' light boosts disease identification
By Grant Banks
November 8, 2010
Scientists have for the first time created "super twisted" light which can be used for more effective disease and virus identification. The process involves polarizing a light beam to create a kind of light corkscrew, then reflecting it off a gold surface to twist the vortex even tighter. Alzheimer’s and Parkinson’s disease are two conditions now being examined using this new technique.
Twisted light, or optical vortexes, have been used in spectroscopy since their discovery in 1974. By twisting the light further, the research team at the University of Glasgow (UG) has greatly improved the efficiency and effectiveness of using spectroscopy for biosensing, making it possible to find protein traces in incredibly small samples of biological material like blood.
“We are very excited by this research,” Dr Malcolm Kadodwala, senior lecturer in the (UG) School of Chemistry said, “Essentially, this twisted light, which does not exist naturally, allows us to detect biological materials at unprecedented low concentrations. We’re now looking to see if this same technique can be adapted to detect a wider range of proteins which are indicative of other diseases. The fact this method requires much less material, just one picogram or million millionth of a gram, for analysis than current techniques and uses a form of light previously unrealized is a big step forward.”
“Due to the nature of the twisted light, it has been shown to be particularly effective at detecting proteins with a structure characteristic of amyloids, insoluble proteins that can stick together to form plaques within different organs in the body. It is these plaques which are thought to play a part in neurodegenerative diseases such as Alzheimer’s, Parkinson’s and CJD, though the reasons for this are unclear,” Kadodwala said.
To twist light like a corkscrew, a beam is passed through a polarizing filter before it is shined onto a specially shaped piece of gold. The technique takes advantage of the fact that, much the same as how polarized sunglasses work, twisted light allows only certain alignments of light waves through.
The findings have been published in Nature Nanotechnology.