Ilett, M, Brydson, R orcid.org/0000-0003-2003-7612, Brown, A et al. (1 more author) (2019) Cryo-analytical STEM of frozen, aqueous dispersions of nanoparticles. Micron, 120. pp. 35-42. ISSN 0968-4328
Abstract
In situ characterisation of nanoparticle dispersion and surface coatings is required to further our understanding of the behaviour of nanoparticles in aqueous suspension. Using cryogenic transmission electron microscopy (cryo-TEM) it is possible to analyse a nanoparticle suspension in the frozen, hydrated state; however, this analysis is often limited to imaging alone. This work demonstrates the first use of analytical scanning TEM (STEM) in the examination of nanoparticles captured in a layer of vitreous ice. Imaging and analysis of frozen hydrated suspensions by both STEM energy dispersive X-ray (EDX) spectroscopy and electron energy loss spectroscopy (EELS) under cryogenic conditions demonstrates the identification and separation of CeO₂ , Fe₂ O₃ , ZnO and Ag nanoparticles in suspension. Damage caused by the electron beam was shown to occur at far higher electron fluences in STEM (<2000 e − /Å 2 ) compared to CTEM (<100 e − /Å 2 ) due to diffusion limited damage by the radiolysis products generated in vitreous ice. Further application of cryo-analytical STEM was undertaken on barium titanate biomarker nanoparticles dispersed in cell culture media to show the formation of a Ca and P rich coating around the nanoparticles when suspended in the media. This previously unreported coating changes the surface chemistry of the biomarkers when exposed to cells. Thus we show that the technique has the potential to advance our understanding of the fundamental behaviour of nanoparticles in complex aqueous suspensions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the terms of the CC-BY-4.0 licence: https://creativecommons.org/licenses/by/4.0/ |
Keywords: | Cryo; Analytical; EDX; EELS; Nanoparticles |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Funding Information: | Funder Grant number EPSRC EP/M028143/1 EPSRC EP/P00122X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Feb 2019 12:00 |
Last Modified: | 25 Jun 2023 21:43 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.micron.2019.01.013 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:142810 |