A false-color fluorescence image of the diamond surface. The small dark circular spots show nitrogen-vacany (NV) centers and the dark vertical stripe is the microwire used to apply the electromagnetic field.Courtesy of IBM ResearchThe device: A miniscule diamond flaw—just two atoms different—could someday enable researchers to image single molecules without resorting to time-consuming and technically exacting X-ray crystallography. The new approach, published today (January 31) in Science, relies on a single electron to detect perturbation in molecular magnetic fields, which can provide clues about the structures of proteins and other molecules.
“It’s quite an exciting breakthrough,” said physicist P. Chris Hammel at Ohio State University, who was not involved in the research. Previous nanoscale strategies worked only at cryogenic temperatures, but the new strategy would be much kinder to biological samples.
The work was inspired by magnetic resonance imaging (MRI), which uses electromagnetic coils to detect the magnetic fields emitted by hydrogen atom protons. But traditional MRI requires many trillions of protons to get a clear image—of a brain, for example—preventing scientists from visualizing anything much smaller than millimeters-wide structures. To detect just a few protons, such as those of a single molecule, scientists would need an atomic-scale sensor.
To construct such a sensor, physicists Daniel Rugar at IBM Research and David Awschalom at the University ...
