Technical Note pubs.acs.org/ac
Mass Spectrometry Imaging on Porous Silicon: Investigating the Distribution of Bioactives in Marine Mollusc Tissues Maurizio Ronci,*,† David Rudd,‡ Taryn Guinan,† Kirsten Benkendorff,‡,§ and Nicolas H. Voelcker*,† †
Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia School of Biological Sciences, Flinders University, Bedford Park, SA 5042, Australia § Marine Ecology Research Centre, Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia ‡
S Supporting Information *
ABSTRACT: Desorption/ionization on porous silicon-mass spectrometry (DIOS-MS) is an attractive alternative to conventional matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the analysis of low molecular weight compounds. Porous silicon (pSi) chips are also suitable as support for mass spectrometry imaging (MSI). Here, we report an implementation of DIOS-MSI using the biosynthetic organs of a marine mollusc for proof of principle. The tissue section is stamped onto a fluorocarbonfunctionalized pSi chip, which extracts and traps small hydrophobic molecules from the tissue under retention of their relative spatial distribution. The section is subsequently removed and the chip is imaged without any remaining tissue. We apply this novel tissue contact printing approach to investigate the distribution of biologically active brominated precursors to Tyrian purple in the hypobranchial gland of the marine mollusc, Dicathais orbita, using DIOS− MSI. The tissue contact printing is also compatible with other types of desorption/ionization surfaces, such as nanoassisted laser desorption/ionization (NALDI) targets.
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conductivity, allowing the silicon structure to act as a laser energy receptacle and achieving efficient analyte ionization and sensitive detection.11,12 Furthermore, chemical modifiers can be covalently bonded to the pSi surface, thus enhancing or modulating the affinity for target compounds in an analogous fashion to conventional solid−liquid extraction.13−15 Therefore, the pSi acts simultaneously as a support, an adsorption substrate, and an ionizing agent thereby facilitating extraction, enrichment, and detection in a single step. However, surprisingly, the potential of NIMS imaging for the detection of small molecules in biological tissue has not been thoroughly evaluated.16 This may be related to the need for extremely thin tissue sections of
