|Posted on July 13, 2015 at 8:45 PM|
Electron microscopy is widely used to image small features at nanoscale. However, this technique has a number of limitations when imaging soft matter, including liquids, polymers, gels, foam and biomolecules. Electron microscopy uses bombarding electrons as the source of illumination, which can destroy soft samples. And its operation under high vacuum means that biomolecules need to be crystallized or they would be destroyed through drying.
Naomi Ginsberg, an assistant professor of Chemistry and Physics at the University of California, Berkeley, and a faculty scientist at the Lawrence Berkeley National Laboratory (LBNL) developed a new approach, called CLAIRE, to take on this challenge. CLAIRE stands for "CathodoLuminescence- Activated Imaging by Resonant Energy transfer," was invented by a group of researchers led by Prof.Ginsberg. It allows electron microscopy imaging of soft matter at the nanoscale with incredible resolution. To avoid the problem of destroying the sample with electrons, Ginsberg and her team inserted an ultrathin scintillating film composed of cerium-doped yttrium aluminum perovskite, about 20 nm thick, between the electron beam and the sample. The electron beam excites the film with low energy, and the film emits energy that is transferred to the sample. The sample radiates and this luminescence can be used to reconstruct the surface of the samples with nanoscale resolution.
While CLAIRE is still being improved and refined, it is clear that it will serve as an important tool for the non-invasive imaging of soft matter at the nanoscale, providing information that has not been available to scientists so far. As an interesting aside, there were two "Claires" associated with the development of CLAIRE: Claire Stachelrodt (undergraduate researcher) and Clarice Aiello (new postdoc)!
Prof. Ginsberg received a 2015 Alfred P. Sloan Foundation fellowship, a 2012 DARPA Young faculty award, and a 2011 Packard fellowship for Science and Engineering. More information about her work can be found on her website, here.
- Written by Eugene Choi, Edited by Paulette Clancy
(Photo credit: Provided by and used with permission from Professor Ginsberg).