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Lehigh University logo

Evan Pretti

Assembly of binary superlattices from multi-flavored DNA-functionalized particles

Department: Chemical and Biomolecular Engineering
Advisor: Jeetain Mittal

Structurally and compositionally ordered lattices assembled from colloidal nanoparticles have a variety of useful applications, including the design of materials for catalysis, photonics, sensing, and selective adsorption. However, many uses for these structures require the precise generation of specific arrangements of particles based upon their interactions with each other. Functionalization of colloid surfaces with complementary DNA sequences has been shown experimentally to allow for control over interparticle interactions. The “multi-flavoring” approach to DNA functionalization allows interactions to be tuned independently between multiple types of particles by adjusting the amounts of different complementary sequences which are grafted to the particle surfaces.

To achieve rational material design, a link must be established between the nature of these interactions and the target structures. In this work, we present a generalized computational approach for predicting the colloidal crystal structures which will be stabilized by given interactions. The method utilizes symmetry groups to systematically enumerate possible candidate structures for a desired crystal stoichiometry, and it employs the basin-hopping algorithm for global optimization to search for those with minimum energies. Additionally, we present the behavior of a specific three-dimensional binary colloid system which can be realized using multi-flavored DNA functionalization, and show that self-assembly of the system into a number of structurally and compositionally ordered lattices can be achieved.

About Evan Pretti:
Evan Pretti is a senior chemical engineering student at Lehigh University. He is currently performing research with Professor Jeetain Mittal using computational techniques to understand the effects that govern the self-assembly of colloidal nanoparticles into ordered structures. He is planning on remaining at Lehigh for a year after graduating under the President’s Scholar Program to continue some research projects, and then pursuing a graduate degree in chemical engineering where he hopes to continue with simulation-related research. Evan is from Bethlehem, Pennsylvania. In his time outside of research and class, he enjoys running, reading, and programming.