Imaging with biomolecular ions generated by massive cluster impact in a time‐of‐flight secondary ion microscope

Abstract

Massive cluster impact (MCI) combined with microscope-mode ion imaging allows rapid imaging using ionized intact biomolecules, with a lateral resolution acceptable for applications with biological samples.

Effects of a proton‐conducting ionic liquid on secondary ion formation in time‐of‐flight secondary ion mass spectrometry

“…In MCI, a shock wave model has been proposed to explain secondary ion formation . Williams and co‐workers have recently demonstrated imaging mass spectrometry of biomolecules using the MCI method combined with a time‐of‐flight secondary ion microscope …”

Time‐of‐flight secondary ion mass spectrometry using a new primary ion beam generated by vacuum electrospray of a protic ionic liquid, propylammonium nitrate

“…Cluster ions such as Au 3 + , Bi 3 + , and C 60 + are widely used as primary ion beams to increase molecular secondary ion yields in TOF‐SIMS . In recent years, massive clusters such as gas clusters and charged droplets have also been used as primary ion beams so as to increase the yields of high‐mass molecular secondary ions with less damage accumulation on analytes …”

Mass Spectra and Yields of Intact Charged Biomolecules Ejected by Massive Cluster Impact for Bioimaging in a Time-of-Flight Secondary Ion Microscope

“…The present work was aimed at determining UY values for ionized intact molecules of biologically interesting species sputtered by MCI under conditions consistent with the ∼3 μm spatial resolution reported earlier. 19 In this paper, we report MCI mass spectra of peptides, lipids, and small proteins showing signals for intact molecules and demonstrate useful ion yields from pure solid samples of these species that are high enough to enable bioimaging with few-micrometer spatial resolution.…”