Programming dynamic pathways to colloidal self-assembly using DNA nanotechnology

DNA is not just the stuff of our genetic code; it is also a means to build new materials. For instance, grafting DNA onto small particles can, in principle, 'program' the particles with information that tells them exactly how to put themselves together-- they 'self-assemble.' Recent advances in our understanding of how this information is compiled into specific interparticle forces have enabled the assembly of an incredible diversity of crystalline phases. However, programmable assembly of other structures, including aperiodic solids, liquids, or mesophases, remains elusive. Furthermore, the dynamic pathways by which DNA-based materials self-assemble are largely unknown. In this talk, I will present experiments showing that combining DNA-grafted particles with free DNA oligomers dispersed in solution can create suspensions with new types of assembly pathways. I will also demonstrate how we can follow and quantify the entire dynamic pathways to self-assembly, such as nucleation and growth, using new experimental approaches, combining microfluidics, video microscopy, and image analysis. Whenever possible, I will describe attempts to understand and model our observations using simple physical arguments. In the future, this work could prove especially useful in nanomaterials research, where a central goal is to manufacture functional materials by growing them directly from solution.