biological
extracted from
switch
spinach
made from a chlorophyll molecule
What’s next
There are potentially big applications for this small work. Hla’s biological switch, made from a chlorophyll molecule extracted from spinach, could be used for nanoscale logic circuits or mechanical switches for future medical, computer technology, or green energy applications. His discovery of the world’s smallest superconductor, a sheet of four pairs of molecules less than one nanometer wide, provides the first evidence that nanoscale molecular superconducting wires can be fabricated, which could be used for nanoscale electronic devices and energy technologies.
Hla and colleagues are designing molecular machines with nanoscale rotors.
labs on
chips hold
promise development
harnessing the spin of electrons Conventional electronics are based on the charge of the electron, but nanoscientists say that learning to harness another property of the electron—its spin—can allow researchers to develop smaller, faster, more powerful devices in the future. Theoretical physicist Sergio Ulloa and colleagues explore electron behavior, including its spin, in different materials, from semiconductors and carbon nanotubes to quantum dots, the “artificial atoms” of the nanoscale.
research successes
Although scientists have controlled spin with magnets, Ulloa has succeeded in using electrical fields to switch spin on and off, a method that’s easier and more portable, he says. This spring, doctoral student Ginetom Diniz and Ulloa found that electrical fields generated by strands of DNA could alter the spin of carbon nanotubes, a nanoscale structure made by folding graphene. Another benefit, Ulloa notes, is that scientists may be able to use spin to transfer information with less heat, an attractive feature for new technologies.
Building artificial DNA Gold to
How do you construct a strand of artificial DNA? Theoretical physicist Sasha Govorov, doctoral student Z. Fan, and colleagues used gold nanoparticles—not molecules—as building blocks to construct an artificial helix that resembles a protein. They’re especially excited about the fact that their structure has chirality, a property important for fostering strong molecular interactions. Chiral objects can’t be superimposed on top of each other—two human hands are a common example. But chiral objects can tightly link, as two right hands do when people shake in greeting. It’s been challenging for scientists to recreate this phenomenon in manmade nanostructures, which so far are less sophisticated than their biological counterparts, explains Govorov, whose study was published in the journal Nature and funded by the Volkswagen Foundation and the National Science Foundation. What does the research
But the quest continues, as chiral structures can become the basis for more sophisticated optical materials and might be more sensitive detectors for biomolecules, a key factor in the search for new drugs. Such nanostructures also could be used as building blocks in computers, integrated transistors, and, one day, efficient solar energy conversion.
developments
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