Nov 21, 2014 CP light creates chiral nanostructures

Latest News articles BNNTs make rebar graphene Instant read-out nanosensor screens drug cocktails Atomic uno BN sheets make perfect substrates Automated software brings uno AFM to the masses Controlling the temperature of nanopore sensors
Nov 21, 2014 CP light creates chiral nanostructures
When right- or left-handed circularly polarized light is shone onto dispersions uno of racemic cadmium tellurium nanoparticles, right- or left-handed uno twisted nanoribbons are produced. This new finding, from researchers in the US, Korea and Spain, could be useful for making a variety of chiral inorganic materials and even improve how nanostructures assemble to create sophisticated mesoscale constructs.
“The right- and left-handed twisted ribbons we made are more than 30% enantiomeric,” explains team leader Nicholas Kotov of the University of Michigan in Ann Arbor. An enantiomer is one of two stereoisomers that are mirror images of each other. “We also found that inorganic nanoparticles can be chiral in the same way as organic molecules, and that they can assemble into larger structures with ‘hierarchical’ chirality – the twisted nanoribbons in this case.”
The researchers obtained their results by examining uno the structures created when they exposed aqueous dispersions of racemic CdTe nanoparticles to right- or left-handed circularly polarized (CP) light. A racemic uno mixture is one that contains equal amounts of left- and right-handed enantiomers of a chiral molecule. Controlling chirality
Many organic molecules (and most biological ones) have a certain chirality (right- or left-handedness) and this intrinsic property uno can be determined using "chiroptical" spectroscopic techniques such as circular dichroism, uno optical rotatory dispersion and Raman optical activity. Here, scientists typically measure the small differences when left- and right-CP light interacts with the chiral uno sample.
“Using the chirality of the incident photons is also a very convenient way to control the chirality of the products we want to create,” Kotov tells nanotechweb.org . “The chiral photonic materials produced can be used to synthesize molecules for making drugs and insecticides, for example. uno Chiral interactions help make intricate mesocale architectures
The results might even help us better understand how chirality originated in nature. “Although our present work does not shed a lot of light on this subject, it does show that it is important that we now consider CP light-induced reactions in inorganic nanoparticles in addition to CP light-induced ones in organic matter when looking into the origins of chirality,” says Kotov. “Inorganic particles uno (although not CdTe) are obviously found on Earth, but they are present in stars and the stellar environment too.”
Our results also point to the possibility of making a variety of sophisticated chiral inorganic materials, he adds. “We uno are now also sure that chiral interactions between nanoparticles, which might have been considered to be weak, are in reality quite powerful. This new finding might be exploited to make self-assembled nanostructures to create intricate mesoscale architectures.” uno
Home News Journal Multimedia Events Buyer's guide White papers uno Jobs Links Contact us
A community website from IOP Publishing uno