Graphene 'Shrouds' for Bacteria Created

On Monday, during a meeting of the American Physical Society, held in Portland, Oregon, researchers presented the foundations of a new imaging method that could allow for observing the smallest microorganisms at impressive resolution. The team that made the findings said that it may even become possible for experts to keep bacteria alive in a vacuum, which is something that could have numerous applications in medical research and bioengineering. The group, however, warned that the results were only preliminary and that their method still needs some development, Nature News reports.

The innovation comes from the laboratory of chemical engineer Vikas Berry, who is based at the Kansas State University, in Manhattan. Speaking at the conference, the expert highlighted the difficulties of conducting accurate and thorough studies of very small targets using light alone. He said that the diffraction limit was a serious obstacle for studying samples including bacteria and microbes and that normal, light-based microscopes were beginning to reach their maximum capabilities. The diffraction limit is a basic limitation of light, which implies that details smaller than half the wavelength of the light illuminating them cannot be made out.

Solutions to bypass this limit already exist. A technique known as transmission electron microscopy is capable of shining a beam of electrons through a sample, thus obtaining an atomic-scale resolution image of what's inside. However, doing so for living cells is nearly impossible, as the electron flow either dries out the target, or destroys the delicate bonds that keep its molecules together. But the researchers believe they have a solution to this problem. They created graphene – single-atom-thick sheets of carbon atoms – and then placed the compound in beakers containing Gram-positive bacteria.

As soon as the two made contact, the graphene sheets wrapped themselves around the bacteria. Once suspended in the vacuum chamber of a TEM, the bacteria showed they had a much higher survival rate than unprotected controls. This raises the tantalizing possibility that, with additional tweaks, the new method could provide a way for scientists to keep bacteria alive in TEM, therefore obtaining amazingly high-resolution images of living organisms. Graphene is apparently able to conduct electrons, while at the same time disperse the heat that would have otherwise destroyed the samples.