Transition metal oxide nanoparticles (TMO Nanoparticles) are commonly utilized as surfaces for surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) in the analysis of small organic biomolecules. SALDI, as opposed to matrix-assisted laser desorption ionization (MALDI), is suitable for analyzing small biomolecules because the inorganic surface reduces interference in the low mass region. With large surface area to volume ratios, low porosity, and inert reaction properties, TMO nanoparticles are ideal surfaces for SALDI MS analysis of organic compounds of this size. Previous experiments have shown TMO nanoparticles such as iron (II,III) oxide (Fe3O4) to be suitable surfaces for the SALDI MS of biomolecules. Herein we present SALDI data comparing Fe3O4 nanoparticles (i.e., 20-30 nm and 15-20 nm) as surfaces in the analysis of small biomolecules, including glucose, sucrose, tryptophan, and met-ala-ser. Signal-to-noise (S/N) ratios were calculated for each analyte using both sizes of Fe3O4 nanoparticles; S/N ratios for LDI trials conducted without nanoparticles were also calculated. The Fe3O4 nanoparticles were characterized using power x-ray diffraction, scanning electron microscopy, and single-point BET measurements. Preliminary data suggests the smaller sized Fe3O4 enhanced the SALDI-MS signal intensities and increased the S/N ratios in comparison to the larger sized Fe3O4, thereby showing the impact of the larger surface area-to-volume ratio.

Influence of transition metal oxide nanoparticle size on surface-assisted laser desorption/ionization mass spectrometry of small biomolecules

2019 Spring National Meeting

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