(728f) DNA-Conjugated Nanoparticle Assemblies Demonstrate a Tunable Mechanical Response

Authors: 
Lequieu, J., University of Chicago
Cordoba, A., University of Chicago
Hinckley, D. M., University of Wisconsin-Madison
de Pablo, J. J., Argonne National Laboratory
Nanoparticles functionalized with short sequences of DNA represent a highly-customizable platform for multiscale materials design. The flexibility and specificity of DNA-mediated interactions facilitates the design of hierarchical structures; with tunable macroscopic properties originating from the nano-scale building blocks of which they're composed. While most recent work has attempted to tune the optical properties of these assemblies, few studies exist that have tried to tune other properties, such as their mechanical response. In this work, we use a detailed molecular model of the DNA-nanoparticle to probe the mechanical properties of DNA-nanoparticle assemblies. We demonstrate that their mechanical properties can be significantly tuned by subtle variations in the linking DNA sequence and is strongly dependent on temperature. Next, we identify the molecular origin of this tunable mechanical response to be closely tied to the connectivity of the nanoparticle network and the anisotropic deformation of the DNA strands conjugated to the nanoparticle surface. The results presented here provides an important initial mechanical characterization of DNA-nanoparticle assemblies can help to dictate their future directions and applications.