Thursday, September 2, 2010
Researchers develop simple technique to visualize atomic-scale structures: We were studying graphene on an atomically flat surface of mica and found some nanoscale island-shaped structures trapped between the graphene and the mica that we didn't expect to see... thought the anomalies might be water, captured and trapped under the graphene... The odd structures became more prevalent at higher humidity, and disappeared under completely dry conditions, leading the researchers to conclude that they indeed were water molecules blanketed by the graphene. Heath and his colleagues realized that the graphene sheet was "atomically conformal"—it hugged the water molecules so tightly, almost like shrink wrap, that it revealed their detailed atomic structure when examined with atomic force microscopy... We could drape graphene over biological molecules—including molecules in at least partially aqueous environments, because you can have water present—and potentially get their 3-D structure," Heath says. It may even be possible to determine the structure of complicated molecules, like protein-protein complexes, "that are very difficult to crystallize," he says.