Near-atomic-scale analysis of frozen water
Published Date: 12/11/2020
Source: phys.org
Advances in transmission electron microscopy (TEM) can allow cryo-imaging of biological and biochemical systems in liquid form, however, such approaches do not possess advanced analytical capabilities. In a new report now published on Science Advances, A. A. El-Zoka and an international team of researchers in Germany, Canada, France, and the U.K., used atom probe tomography to analyze frozen liquids in three-dimensions (3-D) with sub-nanometer scale resolution. In this work, the team first introduced a specimen preparation strategy using nano-porous gold and used ice formed from high-purity deuterated water (hard water) alongside a solution of sodium chloride (50 mM) dissolved in high-purity deuterated water. They then analyzed the gold-ice interface to reveal increased solute concentrations across the interface. The scientists explored a range of experimental conditions to understand atom probe analyses of bulk aqueous specimens. Then they discussed the physical processes associated with the observed phenomena. The study showed the practicality of using frozen water as a carrier for near-atomic-scale analyses of objects in solution via atom probe tomography.