title: Silver Coating for High-Mass-Accuracy Imaging Mass Spectrometry of Fingerprints on Nanostructured Silicon.
abstract: Nanostructure imaging mass spectrometry (NIMS) using porous silicon (pSi) is a key technique for molecular imaging of exogenous and endogenous low molecular weight compounds from fingerprints. However, high-mass-accuracy NIMS can be difficult to achieve as time-of-flight (ToF) mass analyzers, which dominate the field, cannot sufficiently compensate for shifts in measured m/z values. Here, we show internal recalibration using a thin layer of silver (Ag) sputter-coated onto functionalized pSi substrates. NIMS peaks for several previously reported fingerprint components were selected and mass accuracy was compared to theoretical values. Mass accuracy was improved by more than an order of magnitude in several cases. This straightforward method should form part of the standard guidelines for NIMS studies for spatial characterization of small molecules.
authors.forename: Taryn M
authors.initials: TM
authors.lastname: Guinan
authors.forename: Ove J R
authors.initials: OJ
authors.lastname: Gustafsson
authors.affiliation: Nextcell Pty Ltd, Cooperative Research Centre for Cell Therapy Manufacturing, University of South Australia , Mawson Lakes, South Australia 5095, Australia.
authors.forename: Gordon
authors.initials: G
authors.lastname: McPhee
authors.affiliation: School of Chemical and Physical Sciences, Flinders University , General Post Office Box 2100, Adelaide, South Australia 5001, Australia.
authors.forename: Hilton
authors.initials: H
authors.lastname: Kobus
authors.forename: Nicolas H
authors.initials: NH
authors.lastname: Voelcker
mesh_terms: D003878:Dermatoglyphics; D006801:Humans; D013058:Mass Spectrometry; D057054:Molecular Imaging; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D012834:Silver; D012825:Silicon