(678g) Programming DNA-Mediated Colloidal Self-Assembly to Control 3D Binary Superlattice Formation

Authors: 
Zerze, H., Lehigh University
Mahynski, N. A., National Institute of Standards and Technology
Song, M., Lehigh University
Ding, Y., Lehigh University
Shen, V. K., National Institute of Standards and Technology
Mittal, J., Lehigh University
DNA-functionalized colloids are programmable materials that can self-assemble into a variety of crystal structures. Selective hybridization of conjugate base pairs of DNA molecules plays a fundamental role in tailoring the effective colloidal interactions as a useful tool to guide the formation of desired super-lattices. In binary systems, one promising advantage is the ability to independently tune the cross (A-B) and like (A-A or B-B) particle interactions via tethering two different mixtures of suitable strand sequences on different particles, known as multi-flavoring approach. This useful approach also allows controlling one of the like-like pair-interactions (A-A) independently of the other one (B-B). In this work, we conduct computer simulations to investigate the self-assembly of DNA-functionalized colloids into various 3-D binary crystals by programming cross- and like-particle interactions. The molecular dynamics simulations show that the variation of the strength of cross pair-potential relative to like interaction provides selectivity between body-centered cubic (BCC) and close-packed (FCC and HCP) structures. Moreover, changing the two like-interaction strengths (A-A and B-B) relative to one another, controls the composition of the crystals that form. In addition, the transformation kinetics and the thermodynamic stability of the formed structures will be studied.
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