Applications of nanomaterials in ambient ionization mass spectrometry

Ambient ionization mass spectrometry (AIMS) provides direct ionization of analytes on the surface and subsurface of samples under ambient conditions, with minimal sample manipulation. Over the past few years, a series of new ionization techniques have been developed to enhance the capability of AIMS and expand its applications. Simultaneously, the use of nanomaterials in AIMS has attracted considerable attention to improve performance and diversity of applications, through the contribution to selectivity and ionization efficiency, delivered by exploiting the unique properties of the selected nanomaterials. Different nanomaterials including graphene, graphene oxide, single-walled and multi-walled carbon nanotubes, nylon nanofibers, silicon nanowires, and metallic nanoparticles have each been applied across a diverse range of AIMS methods. This review summarises and critically discusses the past decade of the developments by application of nanomaterials in various modes of AIMS, and the consequent advantages and improvements made to this field of mass spectrometry.