The emergence of mass spectrometry for characterizing nanomaterials. Atomically precise nanoclusters and beyond

Abstract

Mass spectrometry (MS) is widely used in molecular science, and is now emerging as a characterization technique for ultra-small nanoparticles. In the field of atomically precise nanoclusters, MS combined to ionization sources such as electrospray and matrix-assisted laser desorption-ionization allows for accurate characterization of the size and charge state of the metal core and of the number of ligands. MS also enables monitoring the evolution of these characteristics during synthesis. When dispersion in nanomaterial composition increases, more relevant metrics are average mass and mass distribution, which can be estimated from electrospray mass spectra using correlation algorithms. Also complex mixtures can be analysed using separation techniques directly coupled with mass spectrometry. For larger nanomaterial compounds, cutting-edge charge detection mass spectrometry can even be used to access the megadalton mass range. In addition, recent MS advancements include the development of new hyphenated techniques such as ion mobility and action spectroscopy, revealing structural details and structure-optical properties relationships in these systems. The present perspective aims at capturing the growing importance and impact of these mass spectrometry based techniques completing the characterization toolbox in materials science.