Establishing a Genetic Code for Unnatural Materials

Nature directs the assembly of enormously complex and highly functional materials through an encoded class of biomolecules that form the foundation of life; these are nucleic acids. The establishment of a similar code for the construction of synthetic, unnatural materials would allow researchers to impart functionality by precisely positioning the atomic components. While such control is exceedingly difficult for atomic and molecular building blocks, control of nanoscale building blocks may be achieved through rational design of surface chemistry. In particular, ligands attached to the surface of nanoparticles can mediate interparticle interactions, independent of particle structure and composition. Our group has shown that nucleic acids can act as powerful ligands to program the spacing and symmetry of nanoparticle building blocks into structurally sophisticated materials. These nucleic acids function as programmable “bonds” between nanoparticle “atoms.” By leveraging innate Watson-Crick base pairing, the sequence of the nucleic acid directs particle assembly, analogous to a nanoscale genetic code. The tunability of these nucleic acids bonds, in terms of length and sequence, has allowed us to define a broad set of design rules to build materials with more than 30 unique lattice symmetries, interparticle spacing spanning an order of magnitude, and multiple well-defined crystal habits. Similar to how nucleic acids function in nature, these materials dynamically respond to biomolecular stimuli, including other nucleic acids, enzymes, and changes in chemical environment, enabling us to tailor structure and properties on demand. This unique genetic approach to materials design yields nanoparticle architectures that can be used to catalyze chemical reactions, manipulate light-matter interactions, investigate energy transfer between nanostructures, and improve our fundamental understanding of crystallization processes.