Programming Self-Assembled Materials With DNA-Coated Colloids

Abstract

Introducing the concept of programmability paves the way for designing complex and intelligent materials, where the materials’ structural information is pre-encoded in the components that build the system. With highly tunable interactions, DNA-coated particles are promising building elements to program materials at the colloidal scale, but several grand challenges have prevented them from assembling into the desired structures and phases. In recent years, the field has seen significant progress in tackling these challenges, which has led to the realization of numerous colloidal structures and dynamics previously inaccessible, including the desirable colloidal diamond structure, that are useful for photonic and various other applications. We review this exciting progress, focusing in detail on how DNA-coated colloids can be designed to have a sophisticatedly tailored surface, shape, patches, as well as controlled kinetics, which are key factors that allow one to program in principle a limitless number of structures. We also share our view on how the field may be directed in future.

Silica/polystyrene bipod-like submicron colloids synthesized by seed-growth dispersion polymerisation as precursors for two-patch silica particles

“…We anticipate these results open up avenues to construct new colloidal building units, such as, for instance, inverse patchy particles [26] for the programmed assembly of new structures with photonic or catalytic properties [27,28]. For instance, the functionalization of the organic patches with azide groups would enable us to graft dibenzocyclooctyne-terminated DNA strands [29], opening the way to the synthesis of colloidal chains with predetermined sequence and colloidal crystals with welldefined architecture.…”

Self-Assembly of DNA-Grafted Colloids: A Review of Challenges

“…DNA grafted particles hold great promise as a tool to create programmed structures [ 6 , 29 , 32 , 48 ]. Ever since the first demonstration of the assembly of DNA-grafted nanoparticles into crystalline structure, by Mirkin [ 30 ] and Alivisatos [ 31 ], there has been extensive research around the possibilities offered by the self-assembly of DNA-grafted particles [ 32 , 33 ], as well as to develop a microscopic understanding of various mechanisms involved [ 49 , 50 , 51 , 52 , 53 , 54 ]. In principle, any target structures can be created using these building blocks, if the particles are functionalized with complementary strands of user defined sequences.…”

“…Another grand challenge, while equilibrating the system towards the prescribed structure, is the kinetic arrest of the system into some random aggregate that fails to anneal further. Except for the cases when the particles are small (smaller than few hundred nanometers), the DNA-grafted particles, generally, find it difficult to re-arrange while they are bound to each other [ 29 , 32 , 45 , 92 ]. Many factors have been held responsible for this kinetic arrest: the grafting density, length and the rigidity of the grafts, inhomogeneity in distribution of the grafts, and the roughness of the particle’s surface [ 92 , 93 , 94 ].…”

“…The other approach, which addresses the above mentioned issues to some extent, is to create building blocks (of some synthetic material) with DNA as binding sites. One such example is of colloids grafted with single strands of DNA; a system that has attracted much interest recently [ 29 , 30 , 31 , 32 , 33 ].…”

“…A subset of the problem is a steep transition of building blocks from dispersed to aggregated phase, as a function of temperature. This sharp transition also contributes to the kinetic arrest [ 29 , 32 , 33 ]. In this review, we will focus on these challenges and cite the studies focused on resolving these issues.…”