Exploring the mobility of nanoscale polyoxometalates using gel electrophoresis

Polyoxometalate clusters encompass a vast library of molecular metal-oxo anions with a large range of mass, size, and charge and are generally formed under one-pot conditions, where many species may exist in solution at any given time. Herein we demonstrate that conventional gel electrophoresis can be used to separate metal oxide based nanomaterials from mixtures, and as a result identify cluster types as a function of their surface charge density. In particular we demonstrate that the nanoscale clusters, contrary to current understanding, have mobility that is a function of the surface charge density at high concentrations. This means that when considering the structural diversity of metal oxide nanomaterials, the variation of charge, size, shape or other structural properties causes a difference in mobility that can be used to both characterise and separate the nanoscale oxides in solution.