Nicholas Kotov1
University of Michigan1
The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. While empirical observations of complex nanoassemblies are abundant, physicochemical mechanisms leading to their geometrical complexity are still puzzling, especially for non-uniformly sized components. These mechanisms are discussed in this talk taking an example of hierarchically organized particles with twisted spikes and other morphologies from polydisperse Au-Cys nanoplatelets [1]. The complexity of these supraparticles is higher than biological counterparts or other complex particles as enumerated by graph theory (GT). Complexity Index (<i>CI</i>) and other GT parameters are applied to a variety of different nanoscale materials to assess their structural organization. As the result of this analysis, we determined that intricate organization Au-Cys supraparticles emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. These findings open a pathway to a large family of colloids with complex architectures and unusual chiroptical and chemical properties.<br/>The design principles for complex chiral nanoassemblies have been extended to engineer drug discovery platforms for Alzheimer syndrome,[3] materials for chiral photonics,[5] biomimetic composites for energy and robotics [2,4] catalysis[6] and antiviral vaccines.[7]<br/><br/><b>References</b><br/>[1] W. Jiang, Z.-B. et al, Emergence of Complexity in Hierarchically Organized Chiral Particles, <i>Science</i>, <b>2020</b>, 368, 6491, 642-648.<br/>[2] Wang, M.; Vecchio, D.; et al Biomorphic Structural Batteries for Robotics. <i>Sci. Robot.</i> <b>2020,</b> 5 (45), eaba1912.<br/>[3] Jun Lu, et al, Enhanced optical asymmetry in supramolecular chiroplasmonic assemblies with long-range order, <i>Science</i>, <b>2021</b>, 371, 6536, 1368<br/>[4] D. Vecchio et al, Structural Analysis of Nanoscale Network Materials Using Graph Theory, <i>ACS Nano</i> <b>2021</b>, 15, 8, 12847–12859.<br/>[5] L. Ohnoutek, et al, Third Harmonic Mie Scattering From Semiconductor Nanohelices, <i>Nature Photonics</i>, <b>2021</b>, conditionally accepted<br/>[6] L. Tang et al. Self-Assembly Mechanism of Complex Corrugated Particles" <i>JACS, </i><b>2021 </b>accepted.<br/>[7] L. Xu, et al Enantiomer-Dependent Immunological Response to Chiral Nanoparticles<b>, 2022</b>, conditionally accepted.