Chemical Physics seminar: Supercrystallography: What Can Nanocrystals Learn from Proteins?

Seminar given by Stefano Toso, Postdoc at the division of Chemical Physics. 

Colloidal superlattices are solids composed of nanocrystals self-assembled into close-packed structures, and are widely studied for the collective properties that emerge from many-particle interactions. Owing to their three-dimensional periodicity, they are often described as “crystals of particles”. But how far does this analogy really extend?

Among crystalline materials, protein crystals offer a particularly instructive parallel. Proteins are comparable in size to nanocrystals (2-10 nm), and both retain a shell of small molecules when they crystallize – water for proteins and ligands for nanoparticles. In structural biology, however, crystals are not the end point of scientific inquiry, but rather tools that enable structure determination via single-crystal X-ray diffraction (SC-XRD).

In this talk, we will discuss how these similarities extend beyond a simple analogy. By employing single-supercrystal X-ray diffraction, we recently identified several striking parallels between CsPbBr₃ perovskite quantum dot superlattices and protein crystals, including similar disorder patterns and conformational changes upon crystallization. Following the lead of structural biology, we will then discuss how crystallography methods can be extended to nanoparticle supercrystals, what opportunities this new approach could offer, and what challenges must be addressed to turn supercrystallography from an exotic concept into an established technique.