N-Heterocyclic carbenes as “smart” gold nanoparticle stabilizers: State-of-the art and perspectives for biomedical applications

The unique properties and high synthetic flexibility of N-heterocyclic carbenes (NHCs) have made them highly attractive tools for the development of new nanomaterials and the fundamental study of their properties. In this review, we focus on the case of NHC-stabilized gold nanoparticles (NHC@AuNPs) with potential for biological applications. AuNPs are ubiquitous in biomedicine, where they serve as versatile scaffolds for drug/gene delivery, biosensing, imaging and therapy. In this context, our review aims at presenting an overview of the relatively few studies reporting on the synthesis and characterization of NHC@AuNPs, with emphasis on the strategies adopted to achieve water-soluble biocompatible nanoparticles. Overall, the possible combinatorial design of NHC ligand shell functionality opens to new perspectives for this relatively unexplored research area.