title: Molecular Imaging of Biological Samples on Nanophotonic Laser Desorption Ionization Platforms.
abstract: Mass spectrometry imaging (MSI) is a comprehensive tool for the analysis of a wide range of biomolecules. The mainstream method for molecular MSI is matrix-assisted laser desorption ionization, however, the presence of a matrix results in spectral interferences and the suppression of some analyte ions. Herein we demonstrate a new matrix-free MSI technique using nanophotonic ionization based on laser desorption ionization (LDI) from a highly uniform silicon nanopost array (NAPA). In mouse brain and kidney tissue sections, the distributions of over 80 putatively annotated molecular species are determined with 40 μm spatial resolution. Furthermore, NAPA-LDI-MS is used to selectively analyze metabolites and lipids from sparsely distributed algal cells and the lamellipodia of human hepatocytes. Our results open the door for matrix-free MSI of tissue sections and small cell populations by nanophotonic ionization.
authors.affiliation: Department of Chemistry, The George Washington University, Washington, DC, 20052, USA.
authors.forename: Sylwia A
authors.initials: SA
authors.lastname: Stopka
authors.affiliation: Department of Chemistry, The George Washington University, Washington, DC, 20052, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Rong
authors.affiliation: Department of Chemistry, The George Washington University, Washington, DC, 20052, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Korte
authors.affiliation: Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC, 2001, USA.
authors.forename: Sridevi
authors.initials: S
authors.lastname: Yadavilli
authors.affiliation: Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC, 2001, USA.
authors.forename: Javad
authors.initials: J
authors.lastname: Nazarian
authors.affiliation: Protea Biosciences Inc., Morgantown, WV, 26505, USA.
authors.forename: Trust T
authors.initials: TT
authors.lastname: Razunguzwa
authors.affiliation: Protea Biosciences Inc., Morgantown, WV, 26505, USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Morris
authors.affiliation: Department of Chemistry, The George Washington University, Washington, DC, 20052, USA. vertes@gwu.edu.
authors.forename: Akos
authors.identifier: http://orcid.org/0000-0001-5186-5352
authors.initials: A
authors.lastname: Vertes
mesh_terms: D000818:Animals; D007834:Lasers; D051379:Mice; D008855:Microscopy, Electron, Scanning; D057054:Molecular Imaging; D017785:Photons; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
keywords: mass spectrometry imaging; silicon nanopost array; small-molecule imaging; tissue section