3D Sub-Nanometer Analysis of Glucose in an Aqueous Solution by Cryo-Atom Probe Tomography

Abstract

Atom Probe Tomography (APT) is currently a well-established technique to analyse the composition of solid materials including metals, semiconductors and ceramics with up to near-atomic resolution. Using an aqueous glucose solution, we now extended the technique to frozen solutions. While the mass signals of the common glucose fragments CxHy and CxOyHz overlap with (H2O)nH from water, we achieved stoichiometrically correct values via signal deconvolution. Density functional theory (DFT) calculations were performed to investigate the stability of the detected pyranose fragments. This paper demonstrates APT’s capabilities to achieve sub-nanometre resolution in tracing whole glucose molecules in a frozen solution by using cryogenic workflows. We use a solution of defined concentration to investigate the chemical and spatial resolution capabilities as a step toward the measurement of biological molecules in solution in 3D with sub-nanometre resolution by using cryo-APT. Our analyses take analytical techniques to a new level, since chemical characterization methods for cryogenically-frozen solutions or biological materials are limited.

A Modular Atom Probe Concept: Design, Operational Aspects, and Performance of an Integrated APT-FIB/SEM Solution

“…The modular version was specifically designed to simplify at least part of the process and eliminate unnecessary sources of error. Thus, the group has succeeded in performing fundamental analyses on frozen liquids (Schwarz et al, 2020(Schwarz et al, , 2021. The preparation of these samples with intermediate transport in a shuttle solution is also possible.…”

Quasi‐“In Situ” Analysis of the Reactive Liquid‐Solid Interface during Magnesium Corrosion Using Cryo‐Atom Probe Tomography

“…In recent years, the development of cryogenic transfer systems for sample transfer between different instruments has made it possible to transfer samples from the glove box to the cryo-focused ion beam (FIB) and then to the atom probe for analysis. [35,36] Cryo-APT has made it possible to study frozen liquids by APT, [37][38][39][40][41] along with liquid-solid interfaces, enabling, e.g., the study of glass corrosion reaction fronts. [42] Here we introduce cryo-APT as a quasi-"in situ" approach to study the reaction front of Mg alloy used as a biodegradable implant during aqueous corrosion to analyze the early-stage corrosion mechanism and the diffusion of alloying elements.…”