Precision at the nanoscale: An ‘ionic’ view of composition, structure and properties

Abstract

The study of matter at the nanoscale has traditionally relied on electron microscopy and optical spectroscopy to relate particle size with emerging properties. Mass spectrometry (MS), although a century-old as an analytical technique, has in recent decades emerged as a central tool for investigating atomically precise clusters (APCs). The introduction of soft ionisation methods such as electrospray ionisation (ESI) and matrix-assisted laser desorption/ionisation (MALDI) has enabled detailed analysis of cluster composition, fragmentation pathways, and structural features. The integration of ion mobility spectrometry with MS has further allowed direct correlations between molecular formula, structure, and stability. At the same time, new developments such as charge-detection MS, ultraviolet photodissociation, and mass photometry have expanded the analytical range to larger and more complex systems. Beyond fundamental characterisation, MS is increasingly being applied to probe intrinsic properties such as ionisation potentials and to support materials applications through cluster deposition and related approaches. This review highlights the expanding role of MS in APC research and the impact of mass spectrometry-based techniques in materials science.