Understanding ligand-protected noble metal nanoclusters at work

Ligand-protected noble metal nanoclusters, commonly termed ‘monolayer-protected metal clusters’ (MPCs), comprise a common set of structures with an inorganic core stabilized by an organic layer of ligand molecules. The choice of the metals in the inorganic core defines the clusters’ physical properties, such as the electronic, optical and magnetic properties, whereas the organic ligand shell defines their solubility and functionality with the surrounding environment. MPCs are currently provoking widespread interest as tunable nanomaterials because they can be engineered, in principle, with atomic precision. In this Review, we discuss the unique features of MPCs that make them ideal nanomaterials for applications in different fields, including catalysis and biological applications such as bioimaging, sensing and targeted drug delivery. We emphasize how understanding these atomically precise nanomaterials requires a tight connection between computational modelling and experimental characterization, which opens unique possibilities for iterative functionalization and tuning for applications.