Nanoparticles Help Scientists Tell Left From Right
Oleg Gang, left, and Mircea Cotlet at Brookhaven's Center for Functional Nanomaterials.
CREDIT: Brookhaven National Laboratory
Have trouble telling left from right? Believe it not, so do molecular scientists. But a new method that amplifies the difference between right-handed and left-handed molecules could make things easier for scientists and lead to the development of new nanomaterials, optical sensors and pharmaceutical drugs.
A team of scientists at the U.S Department of Energy's Brookhaven National Laboratory and Ohio University have developed a way to make determining the handedness, or chirality, of molecules simpler.
In biology, left and right molecular designs are crucial. Living things are only made from left-handed molecules. A left-handed molecule of a particular compound could be an effective drug while its right-handed counterpart is completely inactive.
To help determine which is which, scientists used gold-and-silver cubic nanoparticles to amplify the difference between a left-handed molecule's and a right-handed molecule's response to a particular kind of light known as "circularly polarized" light.
Earlier work showed that molecules respond better to light when coupled with metallic nanoparticles. So researchers experimented with different shapes and compositions of nanoparticles to determine which was best suited for reflecting circularly polarized light.
They found that cubes with a gold centers surrounded by a silver shell were not only effective at picking up a chiral optical signal, they could even amplify these signals.
The optical signals of molecules attached to the gold and silver nanocubes were approximately 100 times stronger than their unattached counterparts.
"Our discovery and methods based on this research could be extremely useful for characterization of biomolecular interactions with drugs, probing protein folding and in other application where stereometric properties are important," said Oleg Gang, a researcher at Brookhaven's Center for Functional Nanomaterials.
Researchers also believe that their work could lead to enhanced designs of metamaterials used for things like energy harvesting and optical telecommunications.