Assessing the potential of sputtered gold nanolayers in mass spectrometry imaging for metabolomics applications

PLoS One. 2018 Dec 12;13(12):e0208908. doi: 10.1371/journal.pone.0208908. eCollection 2018.

Abstract

Mass spectrometry imaging (MSI) is a molecular imaging technique that maps the distribution of molecules in biological tissues with high spatial resolution. The most widely used MSI modality is matrix-assisted laser desorption/ionization (MALDI), mainly due to the large variety of analyte classes amenable for MALDI analysis. However, the organic matrices used in classical MALDI may impact the quality of the molecular images due to limited lateral resolution and strong background noise in the low mass range, hindering its use in metabolomics. Here we present a matrix-free laser desorption/ionization (LDI) technique based on the deposition of gold nanolayers on tissue sections by means of sputter-coating. This gold coating method is quick, fully automated, reproducible, and allows growing highly controlled gold nanolayers, necessary for high quality and high resolution MS image acquisition. The performance of the developed method has been tested through the acquisition of MS images of brain tissues. The obtained spectra showed a high number of MS peaks in the low mass region (m/z below 1000 Da) with few background peaks, demonstrating the ability of the sputtered gold nanolayers of promoting the desorption/ionization of a wide range of metabolites. These results, together with the reliable MS spectrum calibration using gold peaks, make the developed method a valuable alternative for MSI applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gold / chemistry
  • Metabolome / genetics*
  • Metabolomics / methods*
  • Metabolomics / trends
  • Molecular Imaging / methods*
  • Molecular Imaging / trends
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / trends

Substances

  • Gold

Grant support

The MSI project focused on spatial metabolomics within this work has been elaborated is funded by the following institutions: - Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es/portal/site/mineco/?lang_choosen=en) through projects: * TEC2012-31074 to XC, * TEC2015-69076-P to XC, * PR´s predoctoral grant No. BES-2013-065572, * NR’s Juan de la Cierva Incorporación grant No. (IJCI-2015-23158); - Direcció General de Recerca of the Government of Catalonia (http://universitatsirecerca.gencat.cat/en/inici/index.html) through project 2014 SGR 01267; - European Union’s Horizon 2020 research and innovation programme (https://ec.europa.eu/programmes/horizon2020/) under the Marie Sklodowska-Curie grant agreement No. 660034 to NR; - Tobacco Research Disease Related Program (TRDRP) of the University of California http://www.trdrp.org under projects 22RT-0121 and 23DT-0103. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.