Self-assembled nanoparticle dimers with contemporarily relevant properties and emerging applications

Nanoparticle (NP) dimers composed of two adjacent NPs differing in their components, size, or shape display a rich set of interesting properties. NP dimers can be illustrated by their basic nanoscale geometry, which plays a key role in understanding the fundamental mechanisms of their electronic, magnetic and optical properties. The research field of NP dimers has developed rapidly, with wide interest in their construction, novel properties, and emerging applications. Their construction strategies include chemical synthesis processes and chemical and biological assembly processes. Interestingly, the diverse properties of NP dimers can be utilized to achieve functionalities beyond those of the individual particles. Despite the advances in this field, challenges still exist for future research, which will be discussed in this review.