PASADENA, Calif.Researchers at the California Institute of Technology (Caltech) have devised a new techniqueusing a sheet of carbon just one atom thickto visualize the structure of molecules. The technique, which was used to obtain the first direct images of how water coats surfaces at room temperature, can also be used to image a potentially unlimited number of other molecules, including antibodies and other biomolecules.
A paper describing the method and the studies of water layers appears in the September 3 issue of the journal Science.
"Almost all surfaces have a coating of water on them," says James Heath, the Elizabeth W. Gilloon Professor and professor of chemistry at Caltech, "and that water dominates interfacial properties"properties that affect the wear and tear on that surface. While surface coatings of water are ubiquitous, they are also very tough to study, because the water molecules are "in constant flux, and don't sit still long enough to allow measurements," he says.
Quite by accident, Heath and his colleagues developed a technique to pin down the moving molecules, under room-temperature conditions. "It was a happy accidentone that we were smart enough to recognize the significance of," he says. "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."
Graphene, which is composed of a one-atom-thick layer of carbon atoms in a honeycomb-like lattice (like chicken wire, but on an atomic scale), should be completely flat when layered onto an atomically flat surface. Heath and his colleaguesformer Caltech graduate student Ke Xu, now at Harvard University, and graduate student Peigen Caothought the anomalies might be water, captured and trapped under the graphene; water molecules, after all, are everywhere.
To test the idea, the researchers conducted other exp
|Contact: Kathy Svitil|
California Institute of Technology