Conjugated Polymers as a New Class of Dual-Mode Matrices for MALDI Mass Spectrometry and Imaging

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Kilian Horatz - , Leibniz Institute of Polymer Research Dresden, TUD Dresden University of Technology (Author)
  • Marco Giampa - , Bielefeld University (Author)
  • Yevhen Karpov - , Leibniz Institute of Polymer Research Dresden (Author)
  • Karin Sahre - , Leibniz Institute of Polymer Research Dresden (Author)
  • Hanna Bednarz - , Bielefeld University (Author)
  • Anton Kiriy - , Leibniz Institute of Polymer Research Dresden (Author)
  • Brigitte Voit - , Chair of Organic Chemistry of Polymers, Leibniz Institute of Polymer Research Dresden, TUD Dresden University of Technology (Author)
  • Karsten Niehaus - , Bielefeld University (Author)
  • Nikos Hadjichristidis - , King Abdullah University of Science and Technology (Author)
  • Dominik L. Michels - , King Abdullah University of Science and Technology (Author)
  • Franziska Lissel - , Leibniz Institute of Polymer Research Dresden (Author)

Abstract

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) and MALDI MS imaging are ubiquitous analytical methods in medical, pharmaceutical, biological, and environmental research. Currently, there is a strong interest in the investigation of low molecular weight compounds (LMWCs), especially to trace and understand metabolic pathways, requiring the development of new matrix systems that have favorable optical properties and a high ionization efficiency and that are MALDI silent in the LMWC area. In this paper, five conjugated polymers, poly{[N,N'-bis(2-octyldodecyl)-naphtalene-1,4,5,8-bis(dicarboximide)-2,6-diyl}-alt-5,5'(2,2'-bithiophene)} (PNDI(T2)), poly(3-do-decylthiophene-2,5-diyl) (P3DDT), poly{[2,3-bis (3-octyloxyphenyl)quinoxaline-5,8-diyl]-cat-(thiophene-2,5-diyl)} (PT Q1), poly{[N,N'-bis (2-octyldodecyl)-isoindigo-5,5'-diy1]-alt-5,5'(2,2'-bithiophene)} (PII(T2)), and poly(9,9-di-n-octylfluorenyl-2,7-diyl) (P9OFl) are investigated as matrices. The polymers have a strong optical absorption, are solution processable, and can be coated into thin films, allowing a vast reduction in the amount of matrix used. All investigated polymers function as matrices in both positive and negative mode MALDI, classifying them as rare dual-mode matrices, and show a very good analyte ionization ability in both modes. PNDI(T2), P3DDT, PTQ1, and PII(T2) are MALDI silent in the full measurement range (>m/z = 150k), except at high laser intensities. In MALDI MS experiments of single analytes and a complex biological sample, the performance of the polymers was found to be as good as two commonly used matrices (2,5-DHB for positive and 9AA for negative mode measurements). The detection limit of two standard analytes was determined as being below 164 pmol for reserpine and below 245 pmol for cholic acid. Additionally P3DDT was used successfully in first MALDI MS imaging experiments allowing the visualization of the tissue morphology of rat brain sections.

Details

Original languageGerman
Pages (from-to)11416-11423
Number of pages8
JournalJournal of the American Chemical Society
Volume140
Issue number36
Publication statusPublished - 12 Sept 2018
Peer-reviewedYes

External IDs

PubMed 30089208
Scopus 85052325828
ORCID /0000-0002-4531-691X/work/148608062

Keywords

Keywords

  • Assisted-laser-desorption/ionization, Desorption ionization, Tof-ms, Molecular-weight, Ginkgo-biloba, Sample preparation, Tissue, Resolution, Lipids, Time